diff --git a/.gitmodules b/.gitmodules
index 85c12576..b6984f0f 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -20,7 +20,7 @@
 [submodule "ncar-physics"]
         path          = src/physics/ncar_ccpp
 	url           = https://github.com/ESCOMP/atmospheric_physics
-	fxtag         = 045b630a8c3b41d90b6c006392c3907af762dd39
+	fxtag         = d46bb55e233e8f16b4e7a7b5a90352e99c7a5d72
         fxrequired    = AlwaysRequired
         fxDONOTUSEurl = https://github.com/ESCOMP/atmospheric_physics
 [submodule "ccs_config"]
diff --git a/cime_config/cam_autogen.py b/cime_config/cam_autogen.py
index 3d5ed312..e08b1f5b 100644
--- a/cime_config/cam_autogen.py
+++ b/cime_config/cam_autogen.py
@@ -392,7 +392,7 @@ def generate_registry(data_search, build_cache, atm_root, bldroot,
                                    gen_fort_indent, source_mods_dir, atm_root,
                                    logger=_LOGGER, schema_paths=data_search,
                                    error_on_no_validate=True)
-            retcode, reg_file_list, ic_names = retvals
+            retcode, reg_file_list, ic_names, registry_constituents = retvals
             # Raise error if gen_registry failed:
             if retcode != 0:
                 emsg = "ERROR:Unable to generate CAM data structures from {}, err = {}"
@@ -406,14 +406,15 @@ def generate_registry(data_search, build_cache, atm_root, bldroot,
         # Save build details in the build cache
         reg_file_paths = [x.file_path for x in reg_file_list if x.file_path]
         build_cache.update_registry(gen_reg_file, registry_files, dycore,
-                                    reg_file_paths, ic_names)
+                                    reg_file_paths, ic_names, registry_constituents)
     else:
         # If we did not run the registry generator, retrieve info from cache
         reg_file_paths = build_cache.reg_file_list()
         ic_names = build_cache.ic_names()
+        registry_constituents = build_cache.constituents()
     # End if
 
-    return genreg_dir, do_gen_registry, reg_file_paths, ic_names
+    return genreg_dir, do_gen_registry, reg_file_paths, ic_names, registry_constituents
 
 ###############################################################################
 def generate_physics_suites(build_cache, preproc_defs, host_name,
@@ -443,7 +444,8 @@ def generate_physics_suites(build_cache, preproc_defs, host_name,
     suite_search         = [source_mods_dir, atm_suites_path, atm_test_suites_path]
     # Find all scheme metadata files, organized by scheme name
     atm_schemes_path = os.path.join(atm_phys_top_dir, "schemes")
-    source_search    = [source_mods_dir, atm_schemes_path]
+    atm_test_schemes_path = os.path.join(atm_phys_top_dir, "test", "test_schemes")
+    source_search    = [source_mods_dir, atm_schemes_path, atm_test_schemes_path]
     all_scheme_files = _find_metadata_files(source_search, find_scheme_names)
 
     # Find the SDFs specified for this model build
@@ -657,7 +659,7 @@ def generate_physics_suites(build_cache, preproc_defs, host_name,
 ###############################################################################
 def generate_init_routines(build_cache, bldroot, force_ccpp, force_init,
                            source_mods_dir, gen_fort_indent,
-                           cap_database, ic_names):
+                           cap_database, ic_names, registry_constituents):
 ###############################################################################
     """
     Generate the host model initialization source code files
@@ -695,8 +697,8 @@ def generate_init_routines(build_cache, bldroot, force_ccpp, force_init,
         #   within write_init_files (so that write_init_files can be the place
         #   where the source include files are stored).
         source_paths = [source_mods_dir, _REG_GEN_DIR]
-        retmsg = write_init_files(cap_database, ic_names, init_dir,
-                                  _find_file, source_paths,
+        retmsg = write_init_files(cap_database, ic_names, registry_constituents,
+                                  init_dir, _find_file, source_paths,
                                   gen_fort_indent, _LOGGER)
 
         #Check that script ran properly:
diff --git a/cime_config/cam_build_cache.py b/cime_config/cam_build_cache.py
index 2bda072e..70b31853 100644
--- a/cime_config/cam_build_cache.py
+++ b/cime_config/cam_build_cache.py
@@ -226,6 +226,7 @@ def __init__(self, build_cache):
         self.__kind_types = {}
         self.__reg_gen_files = []
         self.__ic_names = {}
+        self.__constituents = []
         if os.path.exists(build_cache):
             # Initialize build cache state
             _, cache = read_xml_file(build_cache)
@@ -252,6 +253,10 @@ def __init__(self, build_cache):
                             # end if
                             itext = clean_xml_text(item)
                             self.__ic_names[stdname].append(itext)
+                        elif item.tag == 'constituent_entry':
+                            stdname = item.get('standard_name')
+                            itext = clean_xml_text(item)
+                            self.__constituents.append(itext)
                         else:
                             emsg = "ERROR: Unknown registry tag, '{}'"
                             raise ValueError(emsg.format(item.tag))
@@ -313,7 +318,7 @@ def __init__(self, build_cache):
         # end if
 
     def update_registry(self, gen_reg_file, registry_source_files,
-                        dycore, reg_file_list, ic_names):
+                        dycore, reg_file_list, ic_names, constituents):
         """Replace the registry cache data with input data
         """
         self.__dycore = dycore
@@ -328,6 +333,7 @@ def update_registry(self, gen_reg_file, registry_source_files,
         # ic_names are the initial condition variable names from the registry,
         # and should already be of type dict:
         self.__ic_names = ic_names
+        self.__constituents = constituents
 
     def update_ccpp(self, suite_definition_files, scheme_files, host_files,
                     xml_files, namelist_meta_files, namelist_groups,
@@ -400,6 +406,10 @@ def write(self):
                 ic_entry.text = ic_name
             # end for
         # end for
+        for stdname in self.__constituents:
+            const_entry = ET.SubElement(registry, 'constituent_entry')
+            const_entry.text = stdname
+        # end for
         # CCPP
         ccpp = ET.SubElement(new_cache, 'CCPP')
         for sfile in self.__sdfs.values():
@@ -603,5 +613,9 @@ def ic_names(self):
         """Return a copy of the registry initial conditions dictionary"""
         return dict(self.__ic_names)
 
+    def constituents(self):
+        """Return a copy of the registry constituents list"""
+        return list(self.__constituents)
+
 #############
 # End of file
diff --git a/cime_config/cam_config.py b/cime_config/cam_config.py
index 80bef16e..afb298a9 100644
--- a/cime_config/cam_config.py
+++ b/cime_config/cam_config.py
@@ -838,7 +838,7 @@ def generate_cam_src(self, gen_fort_indent):
         retvals = generate_registry(data_search, build_cache, self.__atm_root,
                                     self.__bldroot, source_mods_dir,
                                     dyn, gen_fort_indent)
-        reg_dir, force_ccpp, reg_files, ic_names = retvals
+        reg_dir, force_ccpp, reg_files, ic_names, registry_constituents = retvals
 
         #Add registry path to config object:
         reg_dir_desc = "Location of auto-generated registry code."
@@ -871,7 +871,7 @@ def generate_cam_src(self, gen_fort_indent):
         init_dir = generate_init_routines(build_cache, self.__bldroot,
                                           force_ccpp, force_init,
                                           source_mods_dir, gen_fort_indent,
-                                          capgen_db, ic_names)
+                                          capgen_db, ic_names, registry_constituents)
 
         #Add registry path to config object:
         init_dir_desc = "Location of auto-generated physics initialization code."
diff --git a/src/data/air_composition.F90 b/src/data/air_composition.F90
index f202ae97..e84fc837 100644
--- a/src/data/air_composition.F90
+++ b/src/data/air_composition.F90
@@ -346,8 +346,8 @@ subroutine air_composition_init()
             !
             ! CLDICE
             !
-         case('cloud_ice_water_mixing_ratio_wrt_moist_air_and_condensed_water')
-            call air_species_info('cloud_ice_water_mixing_ratio_wrt_moist_air_and_condensed_water', &
+         case('cloud_ice_mixing_ratio_wrt_moist_air_and_condensed_water')
+            call air_species_info('cloud_ice_mixing_ratio_wrt_moist_air_and_condensed_water', &
                                   ix, mw)
             thermodynamic_active_species_idx(icnst) = ix
             thermodynamic_active_species_cp (icnst) = cpice
@@ -408,7 +408,7 @@ subroutine air_composition_init()
             !
             ! GRAUQM
             !
-         case('graupel_water_mixing_ratio_wrt_moist_air_and_conedensed_water')
+         case('graupel_water_mixing_ratio_wrt_moist_air_and_condensed_water')
             call air_species_info('graupel_water_mixing_ratio_wrt_moist_air_and_condensed_water', &
                                   ix, mw)
             thermodynamic_active_species_idx(icnst) = ix
diff --git a/src/data/generate_registry_data.py b/src/data/generate_registry_data.py
index 0b212a9f..e3d5abf9 100755
--- a/src/data/generate_registry_data.py
+++ b/src/data/generate_registry_data.py
@@ -1734,6 +1734,31 @@ def _create_ic_name_dict(registry):
     # end for
     return ic_name_dict
 
+###############################################################################
+def _create_constituent_list(registry):
+###############################################################################
+    """
+    Create a list of all constituents found in the registry.
+    To be used by write_init_files.py - need to keep track
+    of all constituent variables, not just ones required by
+    CCPP metadata, to handle runtime constituents
+    """
+    constituent_list = []
+    for section in registry:
+        if section.tag == 'file':
+            for obj in section:
+                if obj.tag == 'variable':
+                    if obj.get('constituent'):
+                        stdname = obj.get('standard_name')
+                        constituent_list.append(stdname)
+                    # end if (ignore non-constituents)
+                # end if (ignore other node types)
+            # end for
+        # end if (ignore other node types)
+    # end for
+    return constituent_list
+
+
 ###############################################################################
 def gen_registry(registry_file, dycore, outdir, indent,
                  src_mod, src_root, loglevel=None, logger=None,
@@ -1794,6 +1819,7 @@ def gen_registry(registry_file, dycore, outdir, indent,
         retcode = 1
         files = None
         ic_names = None
+        constituents = None
     else:
         library_name = registry.get('name')
         emsg = f"Parsing registry, {library_name}"
@@ -1803,9 +1829,10 @@ def gen_registry(registry_file, dycore, outdir, indent,
                                      src_root, reg_dir, indent, logger)
         # See comment in _create_ic_name_dict
         ic_names = _create_ic_name_dict(registry)
+        registry_constituents = _create_constituent_list(registry)
         retcode = 0 # Throw exception on error
     # end if
-    return retcode, files, ic_names
+    return retcode, files, ic_names, registry_constituents
 
 def main():
     """Function to execute when module called as a script"""
diff --git a/src/data/registry.xml b/src/data/registry.xml
index 4b54088a..4a199b9f 100644
--- a/src/data/registry.xml
+++ b/src/data/registry.xml
@@ -445,5 +445,17 @@
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <ic_file_input_names>RAINQM cnst_RAINQM</ic_file_input_names>
     </variable>
+    <variable local_name="snowqm"
+              standard_name="snow_mixing_ratio_wrt_moist_air_and_condensed_water"
+              units="kg kg-1" type="real" constituent="true">
+      <long_name>snow mass mixing ratio with respect to moist air plus all airborne condensates</long_name>
+      <ic_file_input_names>SNOWQM cnst_SNOWQM</ic_file_input_names>
+    </variable>
+    <variable local_name="grauqm"
+              standard_name="graupel_water_mixing_ratio_wrt_moist_air_and_condensed_water"
+              units="kg kg-1" type="real" constituent="true">
+      <long_name>graupel mass mixing ratio with respect to moist air plus all airborne condensates</long_name>
+      <ic_file_input_names>GRAUQM cnst_GRAUQM</ic_file_input_names>
+    </variable>
   </file>
 </registry>
diff --git a/src/data/write_init_files.py b/src/data/write_init_files.py
index 03e0bd93..b0f92d1c 100644
--- a/src/data/write_init_files.py
+++ b/src/data/write_init_files.py
@@ -47,7 +47,7 @@
 #Main function
 ##############
 
-def write_init_files(cap_database, ic_names, outdir,
+def write_init_files(cap_database, ic_names, registry_constituents, outdir,
                      file_find_func, source_paths, indent, logger,
                      phys_check_filename=None, phys_input_filename=None):
 
@@ -131,7 +131,7 @@ def write_init_files(cap_database, ic_names, outdir,
 
     # Gather all the host model variables that are required by
     #    any of the compiled CCPP physics suites.
-    host_vars, constituent_set, retmsg = gather_ccpp_req_vars(cap_database)
+    host_vars, constituent_set, retmsg = gather_ccpp_req_vars(cap_database, registry_constituents)
 
     # Quit now if there are missing variables
     if retmsg:
@@ -174,12 +174,12 @@ def write_init_files(cap_database, ic_names, outdir,
         # end for
 
         # Write public parameters:
-        retvals = write_ic_params(outfile, host_vars, ic_names)
+        retvals = write_ic_params(outfile, host_vars, ic_names, registry_constituents)
         ic_names, ic_max_len, stdname_max_len = retvals
 
         # Write initial condition arrays:
         write_ic_arrays(outfile, ic_names, ic_max_len,
-                        stdname_max_len, host_vars)
+                        stdname_max_len, host_vars, registry_constituents)
 
         # Add "contains" statement:
         outfile.end_module_header()
@@ -299,7 +299,7 @@ def _find_and_add_host_variable(stdname, host_dict, var_dict):
     return missing_vars
 
 ##############################################################################
-def gather_ccpp_req_vars(cap_database):
+def gather_ccpp_req_vars(cap_database, registry_constituents):
     """
     Generate a list of host-model and constituent variables
     required by the CCPP physics suites potentially being used
@@ -332,13 +332,12 @@ def gather_ccpp_req_vars(cap_database):
                 (stdname not in req_vars) and
                 (stdname not in _EXCLUDED_STDNAMES)):
                 if is_const:
-                    #Variable is a constituent, so may not be known
-                    #until runtime, but still need variable names in order
-                    #to read from a file if need be:
-                    req_vars[stdname] = cvar
-
                     #Add variable to constituent set:
                     constituent_vars.add(stdname)
+                    #Add variable to required variable list if it's not a registry constituent
+                    if stdname not in registry_constituents:
+                        req_vars[stdname] = cvar
+                    # end if
                 else:
                     # We need to work with the host model version of this variable
                     missing = _find_and_add_host_variable(stdname, host_dict,
@@ -360,7 +359,7 @@ def gather_ccpp_req_vars(cap_database):
 #FORTRAN WRITING FUNCTIONS
 ##########################
 
-def write_ic_params(outfile, host_vars, ic_names):
+def write_ic_params(outfile, host_vars, ic_names, registry_constituents):
 
     """
     Write public parameter declarations needed
@@ -371,7 +370,7 @@ def write_ic_params(outfile, host_vars, ic_names):
 
     #Create new Fortran integer parameter to store total number of variables:
     outfile.comment("Total number of physics-related variables:", 1)
-    num_pvars = len(host_vars)
+    num_pvars = len(host_vars) + len(registry_constituents)
     outfile.write(f"integer, public, parameter :: phys_var_num = {num_pvars}",
                   1)
     num_cvars = len(_EXCLUDED_STDNAMES)
@@ -420,7 +419,7 @@ def write_ic_params(outfile, host_vars, ic_names):
 ######
 
 def write_ic_arrays(outfile, ic_name_dict, ic_max_len,
-                    stdname_max_len, host_vars):
+                    stdname_max_len, host_vars, registry_constituents):
 
     """
     Write initial condition arrays to store
@@ -429,7 +428,7 @@ def write_ic_arrays(outfile, ic_name_dict, ic_max_len,
     """
 
     #Create variable name array string lists:
-    num_input_vars = len(host_vars)
+    num_input_vars = len(host_vars) + len(registry_constituents)
     stdname_strs = []
     ic_name_strs = []
 
@@ -446,6 +445,10 @@ def write_ic_arrays(outfile, ic_name_dict, ic_max_len,
     #    for each variable with the proper length, <stdname_max_len>:
     for hvar in host_vars:
         var_stdname = hvar.get_prop_value('standard_name')
+        if var_stdname in registry_constituents:
+            # skip registry constituents; we'll tackle these after
+            continue
+        # end if
 
         # Create standard_name string with proper size, and append to list:
         stdname_strs.append(f"'{var_stdname: <{stdname_max_len}}'")
@@ -466,6 +469,26 @@ def write_ic_arrays(outfile, ic_name_dict, ic_max_len,
         ic_name_strs.append(', '.join(f"'{n}'" for n in ic_names_with_spaces))
     # end for
 
+    # Add any constituent variables:
+    for const in registry_constituents:
+        stdname_strs.append(f"'{const: <{stdname_max_len}}'")
+
+        #Extract input (IC) names list:
+        ic_names = ic_name_dict[const]
+
+        # Determine number of IC names for variable:
+        ic_name_num = len(ic_names)
+
+        #Pad the ic_names to ic_max_len:
+        ic_names_with_spaces = [f"{x: <{ic_max_len}}" for x in ic_names]
+        if ic_name_num < max_ic_num:
+            ic_names_with_spaces.extend(fake_ic_names[:-ic_name_num])
+        # end if
+
+        #Append new ic_names to string list:
+        ic_name_strs.append(', '.join(f"'{n}'" for n in ic_names_with_spaces))
+    # end if
+
     #Write arrays to Fortran file:
     #----------------------------
 
@@ -551,6 +574,18 @@ def write_ic_arrays(outfile, ic_name_dict, ic_max_len,
         #Write line to file:
         outfile.write(log_arr_str, 2)
     # end for
+    arr_suffix = ', &'
+    for var_num, var_name in enumerate(registry_constituents):
+        # If at the end of the list, then update suffix:
+        if var_num == num_input_vars-len(host_vars)-1:
+            arr_suffix = ' /)'
+        # end if
+        #Set array values:
+        log_arr_str = '.false.' + arr_suffix
+
+        #Write line to file:
+        outfile.write(log_arr_str, 2)
+    # end for
 
     outfile.blank_line()
 
@@ -566,7 +601,6 @@ def write_ic_arrays(outfile, ic_name_dict, ic_max_len,
     #variable is a parameter:
     arr_suffix = ', &'
     for var_num, hvar in enumerate(host_vars):
-        var_stdname = hvar.get_prop_value('standard_name')
         #If at the end of the list, then update suffix:
         if var_num == num_input_vars-1:
             arr_suffix = ' /)'
@@ -580,6 +614,17 @@ def write_ic_arrays(outfile, ic_name_dict, ic_max_len,
         #Write line to file:
         outfile.write(log_arr_str, 2)
     # end for
+    arr_suffix = ', &'
+    for var_num, varname in enumerate(registry_constituents):
+        #If at the end of the list, then update suffix:
+        if var_num == num_input_vars-len(host_vars)-1:
+            arr_suffix = ' /)'
+        # end if
+        #Set array values:
+        log_arr_str = 'UNINITIALIZED' + arr_suffix
+        #Write line to file:
+        outfile.write(log_arr_str, 2)
+    # end for
 
     outfile.blank_line()
     #----------------------------
@@ -842,10 +887,13 @@ def write_phys_read_subroutine(outfile, host_dict, host_vars, host_imports,
                  ["physics_data", ["read_field", "find_input_name_idx",
                                    "no_exist_idx", "init_mark_idx",
                                    "prot_no_init_idx", "const_idx"]],
-                 ["cam_ccpp_cap", ["ccpp_physics_suite_variables", "cam_constituents_array", "cam_model_const_properties"]],
+                 ["cam_ccpp_cap", ["ccpp_physics_suite_variables", 
+                                   "cam_constituents_array", 
+                                   "cam_model_const_properties"]],
                  ["ccpp_kinds", ["kind_phys"]],
                  [phys_check_fname_str, ["phys_var_num", "phys_var_stdnames",
-                                         "input_var_names", "std_name_len"]],
+                                         "input_var_names", "std_name_len",
+                                         "is_initialized"]],
                  ["ccpp_constituent_prop_mod", ["ccpp_constituent_prop_ptr_t"]],
                  ["cam_logfile", ["iulog"]]]
 
@@ -888,10 +936,12 @@ def write_phys_read_subroutine(outfile, host_dict, host_vars, host_imports,
     outfile.write("character(len=2)           :: sep3            !String separator used to print err messages", 2)
     outfile.write("real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)", 2)
     outfile.write("logical                    :: var_found       !Bool to determine if consituent found in data files", 2)
+    outfile.write("character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name", 2)
     outfile.blank_line()
     outfile.comment("Fields needed for getting default data value for constituents", 2)
     outfile.write("type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)", 2)
     outfile.write("real(kind=kind_phys)                       :: constituent_default_value", 2)
+    outfile.write("real(kind=kind_phys)                       :: constituent_min_value", 2)
     outfile.write("integer                                    :: constituent_errflg", 2)
     outfile.write("character(len=512)                         :: constituent_errmsg", 2)
     outfile.write("logical                                    :: constituent_has_default", 2)
@@ -982,48 +1032,7 @@ def write_phys_read_subroutine(outfile, host_dict, host_vars, host_imports,
     # Handle the case where the required variable is a constituent
     outfile.write("case (const_idx)", 5)
     outfile.blank_line()
-    outfile.comment("If an index was found in the constituent hash table, then read in the data to that index of the constituent array", 6)
-    outfile.blank_line()
-    outfile.write("var_found = .false.", 6)
-    outfile.write("field_data_ptr => cam_constituents_array()", 6)
-    outfile.blank_line()
-    outfile.comment("Check if constituent standard name in registered SIMA standard names list:", 6)
-    outfile.write("if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then", 6)
-    outfile.comment("Find array index to extract correct input names:", 7)
-    outfile.write("do n=1, phys_var_num", 7)
-    outfile.write("if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then", 8)
-    outfile.write("const_input_idx = n", 9)
-    outfile.write("exit", 9)
-    outfile.write("end if", 8)
-    outfile.write("end do", 7)
-    outfile.write("call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)", 7)
-    outfile.write("else", 6)
-    outfile.comment("If not in standard names list, then just use constituent name as input file name:",7)
-    outfile.write("call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)", 7)
-    outfile.write("end if", 6)
-    outfile.write("if(.not. var_found) then", 6)
-    outfile.write("const_props => cam_model_const_properties()", 7)
-    outfile.write("constituent_has_default = .false.", 7)
-    outfile.write("call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)", 7)
-    outfile.write("if (constituent_errflg /= 0) then", 7)
-    outfile.write("call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)", 8)
-    outfile.write("end if", 7)
-    outfile.write("if (constituent_has_default) then", 7)
-    outfile.write("call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)", 8)
-    outfile.write("if (constituent_errflg /= 0) then", 8)
-    outfile.write("call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)", 9)
-    outfile.write("end if", 8)
-    outfile.write("field_data_ptr(:,:,constituent_idx) = constituent_default_value", 8)
-    outfile.write("if (masterproc) then", 8)
-    outfile.write("write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ', constituent_default_value", 9)
-    outfile.write("end if", 8)
-    outfile.write("else", 7)
-    outfile.write("field_data_ptr(:,:,constituent_idx) = 0._kind_phys", 8)
-    outfile.write("if (masterproc) then", 8)
-    outfile.write("write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'", 9)
-    outfile.write("end if", 8)
-    outfile.write("end if", 7)
-    outfile.write("end if", 6)
+    outfile.comment("If an index was found in the constituent hash table, then do nothing, this will be handled later", 6)
     outfile.blank_line()
 
     # start default case steps:
@@ -1073,6 +1082,62 @@ def write_phys_read_subroutine(outfile, host_dict, host_vars, host_imports,
     # End suite loop:
     outfile.write(" end do !CCPP suites", 2)
     outfile.blank_line()
+    
+    # Read in constituent data
+    outfile.comment("Read in constituent variables if not using init variables", 2)
+    outfile.write("field_data_ptr => cam_constituents_array()", 2)
+    outfile.write("const_props => cam_model_const_properties()", 2)
+    outfile.blank_line()
+    outfile.comment("Iterate over all registered constituents", 2)
+    outfile.write("do constituent_idx = 1, size(const_props)", 2)
+    outfile.write("var_found = .false.", 3)
+    outfile.comment("Check if constituent standard name in registered SIMA standard names list:", 3)
+    outfile.write("call const_props(constituent_idx)%standard_name(std_name)", 3)
+    outfile.write("if(any(phys_var_stdnames == trim(std_name))) then", 3)
+    outfile.comment("Don't read the variable in if it's already initialized", 4)
+    outfile.write("if (is_initialized(std_name)) then", 4)
+    outfile.write("cycle", 5)
+    outfile.write("end if", 4)
+    outfile.comment("Find array index to extract correct input names:", 4)
+    outfile.write("do n=1, phys_var_num", 4)
+    outfile.write("if(trim(phys_var_stdnames(n)) == trim(std_name)) then", 5)
+    outfile.write("const_input_idx = n", 6)
+    outfile.write("exit", 6)
+    outfile.write("end if", 5)
+    outfile.write("end do", 4)
+    outfile.write("call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)", 4)
+    outfile.write("else", 3)
+    outfile.comment("If not in standard names list, then just use constituent name as input file name:",4)
+    outfile.write("call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)", 4)
+    outfile.write("end if", 3)
+    outfile.write("if(.not. var_found) then", 3)
+    outfile.write("constituent_has_default = .false.", 4)
+    outfile.write("call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)", 4)
+    outfile.write("if (constituent_errflg /= 0) then", 4)
+    outfile.write("call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)", 5)
+    outfile.write("end if", 4)
+    outfile.write("if (constituent_has_default) then", 4)
+    outfile.write("call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)", 5)
+    outfile.write("if (constituent_errflg /= 0) then", 5)
+    outfile.write("call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)", 6)
+    outfile.write("end if", 5)
+    outfile.write("field_data_ptr(:,:,constituent_idx) = constituent_default_value", 5)
+    outfile.write("if (masterproc) then", 5)
+    outfile.write("write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value", 6)
+    outfile.write("end if", 5)
+    outfile.write("else", 4)
+    outfile.comment("Intialize to constituent's configured minimum value", 5)
+    outfile.write("call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)", 5)
+    outfile.write("field_data_ptr(:,:,constituent_idx) = constituent_min_value", 5)
+    outfile.write("if (masterproc) then", 5)
+    outfile.write("write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'", 6)
+    outfile.write("end if", 5)
+    outfile.write("end if", 4)
+    outfile.write("end if", 3)
+    outfile.write("end do", 2)
+    outfile.blank_line()
+
+    # start default case steps:
 
     # End subroutine:
     outfile.write("end subroutine physics_read_data", 1)
@@ -1150,7 +1215,9 @@ def write_phys_check_subroutine(outfile, host_dict, host_vars, host_imports,
                  ["physics_data", ["check_field", "find_input_name_idx",
                                    "no_exist_idx", "init_mark_idx",
                                    "prot_no_init_idx", "const_idx"]],
-                 ["cam_ccpp_cap", ["ccpp_physics_suite_variables", "cam_advected_constituents_array"]],
+                 ["cam_ccpp_cap", ["ccpp_physics_suite_variables",
+                                   "cam_advected_constituents_array",
+                                   "cam_model_const_properties"]],
                  ["cam_constituents", ["const_get_index"]],
                  ["ccpp_kinds", ["kind_phys"]],
                  ["cam_logfile", ["iulog"]],
@@ -1158,6 +1225,7 @@ def write_phys_check_subroutine(outfile, host_dict, host_vars, host_imports,
                  ["phys_vars_init_check", ["is_read_from_file"]],
                  ["ioFileMod", ["cam_get_file"]],
                  ["cam_pio_utils", ["cam_pio_openfile", "cam_pio_closefile"]],
+                 ["ccpp_constituent_prop_mod", ["ccpp_constituent_prop_ptr_t"]],
                  [phys_check_fname_str, ["phys_var_num",
                                          "phys_var_stdnames",
                                          "input_var_names",
@@ -1205,7 +1273,9 @@ def write_phys_check_subroutine(outfile, host_dict, host_vars, host_imports,
     outfile.write("logical                    :: file_found", 2)
     outfile.write("logical                    :: is_first", 2)
     outfile.write("logical                    :: is_read", 2)
+    outfile.write("character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name", 2)
     outfile.write("real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)", 2)
+    outfile.write("type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)", 2)
     outfile.blank_line()
 
     # Initialize variables:
@@ -1269,24 +1339,7 @@ def write_phys_check_subroutine(outfile, host_dict, host_vars, host_imports,
     outfile.comment("First check if the required variable is a constituent:", 4)
     outfile.write("call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)", 4)
     outfile.write("if (constituent_idx > -1) then", 4)
-    outfile.comment("The required variable is a constituent. Call check variable routine on the relevant index of the constituent array", 5)
-    outfile.write("field_data_ptr => cam_advected_constituents_array()", 5)
-    outfile.blank_line()
-    outfile.comment("Check if constituent standard name in registered SIMA standard names list:", 5)
-    outfile.write("if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then", 5)
-    outfile.comment("Find array index to extract correct input names:", 6)
-    outfile.write("do n=1, phys_var_num", 6)
-    outfile.write("if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then", 7)
-    outfile.write("const_input_idx = n", 8)
-    outfile.write("exit", 8)
-    outfile.write("end if", 7)
-    outfile.write("end do", 6)
-    outfile.write("call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)", 6)
-    outfile.write("else", 5)
-    outfile.comment("If not in standard names list, then just use constituent name as input file name:",6)
-    outfile.write("call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx), ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)", 6)
-    outfile.write("end if", 5)
-
+    outfile.write("cycle", 5)
     outfile.write("else", 4)
     outfile.comment("The required variable is not a constituent. Check if the variable was read from a file", 5)
 
@@ -1322,6 +1375,27 @@ def write_phys_check_subroutine(outfile, host_dict, host_vars, host_imports,
     # End suite loop:
     outfile.write("end do !CCPP suites", 2)
     outfile.blank_line()
+    outfile.comment("Check constituent variables", 2)
+    outfile.write("field_data_ptr => cam_advected_constituents_array()", 2)
+    outfile.write("const_props => cam_model_const_properties()", 2)
+    outfile.blank_line()
+    outfile.write("do constituent_idx = 1, size(const_props)", 2)
+    outfile.comment("Check if constituent standard name in registered SIMA standard names list:", 3)
+    outfile.write("call const_props(constituent_idx)%standard_name(std_name)", 3)
+    outfile.write("if(any(phys_var_stdnames == std_name)) then", 3)
+    outfile.comment("Find array index to extract correct input names:", 4)
+    outfile.write("do n=1, phys_var_num", 4)
+    outfile.write("if(trim(phys_var_stdnames(n)) == trim(std_name)) then", 5)
+    outfile.write("const_input_idx = n", 6)
+    outfile.write("exit", 6)
+    outfile.write("end if", 5)
+    outfile.write("end do", 4)
+    outfile.write("call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value, is_first)", 4)
+    outfile.write("else", 3)
+    outfile.comment("If not in standard names list, then just use constituent name as input file name:",4)
+    outfile.write("call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value, is_first)", 4)
+    outfile.write("end if", 3)
+    outfile.write("end do", 2)
 
     # Close check file
     outfile.comment("Close check file:", 2)
diff --git a/src/physics/ncar_ccpp b/src/physics/ncar_ccpp
index 045b630a..29c7663a 160000
--- a/src/physics/ncar_ccpp
+++ b/src/physics/ncar_ccpp
@@ -1 +1 @@
-Subproject commit 045b630a8c3b41d90b6c006392c3907af762dd39
+Subproject commit 29c7663a68d9b66bfe7926a56a595dbcbf2c385c
diff --git a/test/unit/sample_files/build_cache_files/update_reg_build_cache.xml b/test/unit/sample_files/build_cache_files/update_reg_build_cache.xml
index e773ee2c..5a4273b9 100644
--- a/test/unit/sample_files/build_cache_files/update_reg_build_cache.xml
+++ b/test/unit/sample_files/build_cache_files/update_reg_build_cache.xml
@@ -8,6 +8,8 @@
       <reg_gen_file>tmp/cam_build_cache/test_reg.xml</reg_gen_file>
       <ic_name_entry standard_name="Only_had_a">heart</ic_name_entry>
       <ic_name_entry standard_name="Only_had_a">brain</ic_name_entry>
+      <constituent_entry>cnst_1</constituent_entry>
+      <constituent_entry>cnst_2</constituent_entry>
    </registry>
    <CCPP>
       <SDF file_path="/behind/curtain/suite_wizard.xml" hash="ade45dea32a6f279957735596a147efddd061f9c"/>
diff --git a/test/unit/sample_files/write_init_files/phys_vars_init_check_cnst.F90 b/test/unit/sample_files/write_init_files/phys_vars_init_check_cnst.F90
index 6849ef70..ceee4cb2 100644
--- a/test/unit/sample_files/write_init_files/phys_vars_init_check_cnst.F90
+++ b/test/unit/sample_files/write_init_files/phys_vars_init_check_cnst.F90
@@ -40,7 +40,7 @@ module phys_vars_init_check_cnst
    integer, public, parameter :: std_name_len = 25
 
    ! Max length of input (IC) file variable names:
-   integer, public, parameter :: ic_name_len = 13
+   integer, public, parameter :: ic_name_len = 12
 
    ! Physics-related input variable standard names:
    character(len=25), public, protected :: phys_var_stdnames(phys_var_num) = (/ &
@@ -66,10 +66,10 @@ module phys_vars_init_check_cnst
       "suite_name                          ", &
       "suite_part                          " /)
    !Array storing all registered IC file input names for each variable:
-   character(len=13), public, protected :: input_var_names(2, phys_var_num) = reshape((/ &
-      'theta        ', 'pot_temp     ', &
-      'slp          ', 'sea_lev_pres ', &
-      'COOL_CAT     ', 'cnst_COOL_CAT' /), (/2, phys_var_num/))
+   character(len=12), public, protected :: input_var_names(2, phys_var_num) = reshape((/ &
+      'theta       ', 'pot_temp    ', &
+      'slp         ', 'sea_lev_pres', &
+      'COOL_CAT    ', 'cnst_COOL_CAT' /), (/2, phys_var_num/))
 
    ! Array indicating whether or not variable is protected:
    logical, public, protected :: protected_vars(phys_var_num)= (/ &
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_4D.F90 b/test/unit/sample_files/write_init_files/physics_inputs_4D.F90
index 75efc762..250179c8 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_4D.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_4D.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,              only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                only: kind_phys
-      use phys_vars_init_check_4D,   only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_4D,   only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
       use cam_logfile,               only: iulog
       use physics_types_4D,          only: slp, theta
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,23 +170,78 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
-      use pio,                     only: file_desc_t, pio_nowrite
-      use cam_abortutils,          only: endrun
-      use shr_kind_mod,            only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
-      use physics_data,            only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,            only: ccpp_physics_suite_variables, cam_advected_constituents_array
-      use cam_constituents,        only: const_get_index
-      use ccpp_kinds,              only: kind_phys
-      use cam_logfile,             only: iulog
-      use spmd_utils,              only: masterproc
-      use phys_vars_init_check,    only: is_read_from_file
-      use ioFileMod,               only: cam_get_file
-      use cam_pio_utils,           only: cam_pio_openfile, cam_pio_closefile
-      use phys_vars_init_check_4D, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
-      use physics_types_4D,        only: slp, theta
+      use pio,                       only: file_desc_t, pio_nowrite
+      use cam_abortutils,            only: endrun
+      use shr_kind_mod,              only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
+      use physics_data,              only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
+      use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
+      use cam_constituents,          only: const_get_index
+      use ccpp_kinds,                only: kind_phys
+      use cam_logfile,               only: iulog
+      use spmd_utils,                only: masterproc
+      use phys_vars_init_check,      only: is_read_from_file
+      use ioFileMod,                 only: cam_get_file
+      use cam_pio_utils,             only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
+      use phys_vars_init_check_4D,   only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use physics_types_4D,          only: slp, theta
 
       ! Dummy arguments
       character(len=SHR_KIND_CL), intent(in) :: file_name
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -344,6 +341,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_bvd.F90 b/test/unit/sample_files/write_init_files/physics_inputs_bvd.F90
index 46cc2b53..99fa3c3d 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_bvd.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_bvd.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,              only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                only: kind_phys
-      use phys_vars_init_check_bvd,  only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_bvd,  only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
       use cam_logfile,               only: iulog
       use physics_types_bad_vertdim, only: slp, theta
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,6 +170,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -219,7 +231,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,            only: endrun
       use shr_kind_mod,              only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,              only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,          only: const_get_index
       use ccpp_kinds,                only: kind_phys
       use cam_logfile,               only: iulog
@@ -227,6 +239,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,      only: is_read_from_file
       use ioFileMod,                 only: cam_get_file
       use cam_pio_utils,             only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_bvd,  only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_bad_vertdim, only: slp, theta
 
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -344,6 +341,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_cnst.F90 b/test/unit/sample_files/write_init_files/physics_inputs_cnst.F90
index 2289adfd..218d7f48 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_cnst.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_cnst.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,              only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                only: kind_phys
-      use phys_vars_init_check_cnst, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_cnst, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
       use cam_logfile,               only: iulog
       use physics_types_simple,      only: slp, theta
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,6 +170,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -219,7 +231,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,            only: endrun
       use shr_kind_mod,              only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,              only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,          only: const_get_index
       use ccpp_kinds,                only: kind_phys
       use cam_logfile,               only: iulog
@@ -227,6 +239,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,      only: is_read_from_file
       use ioFileMod,                 only: cam_get_file
       use cam_pio_utils,             only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_cnst, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_simple,      only: slp, theta
 
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -345,6 +342,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_ddt.F90 b/test/unit/sample_files/write_init_files/physics_inputs_ddt.F90
index de9adfea..d5675487 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_ddt.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_ddt.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,              only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                only: kind_phys
-      use phys_vars_init_check_ddt,  only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_ddt,  only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
       use cam_logfile,               only: iulog
       use physics_types_ddt,         only: phys_state, slp
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,23 +170,78 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
-      use pio,                      only: file_desc_t, pio_nowrite
-      use cam_abortutils,           only: endrun
-      use shr_kind_mod,             only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
-      use physics_data,             only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,             only: ccpp_physics_suite_variables, cam_advected_constituents_array
-      use cam_constituents,         only: const_get_index
-      use ccpp_kinds,               only: kind_phys
-      use cam_logfile,              only: iulog
-      use spmd_utils,               only: masterproc
-      use phys_vars_init_check,     only: is_read_from_file
-      use ioFileMod,                only: cam_get_file
-      use cam_pio_utils,            only: cam_pio_openfile, cam_pio_closefile
-      use phys_vars_init_check_ddt, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
-      use physics_types_ddt,        only: phys_state, slp
+      use pio,                       only: file_desc_t, pio_nowrite
+      use cam_abortutils,            only: endrun
+      use shr_kind_mod,              only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
+      use physics_data,              only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
+      use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
+      use cam_constituents,          only: const_get_index
+      use ccpp_kinds,                only: kind_phys
+      use cam_logfile,               only: iulog
+      use spmd_utils,                only: masterproc
+      use phys_vars_init_check,      only: is_read_from_file
+      use ioFileMod,                 only: cam_get_file
+      use cam_pio_utils,             only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
+      use phys_vars_init_check_ddt,  only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use physics_types_ddt,         only: phys_state, slp
 
       ! Dummy arguments
       character(len=SHR_KIND_CL), intent(in) :: file_name
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -345,6 +342,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_ddt2.F90 b/test/unit/sample_files/write_init_files/physics_inputs_ddt2.F90
index 2dc7d3b9..57ea3c19 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_ddt2.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_ddt2.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,              only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                only: kind_phys
-      use phys_vars_init_check_ddt2, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_ddt2, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
       use cam_logfile,               only: iulog
       use physics_types_ddt2,        only: phys_state
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,6 +170,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -219,7 +231,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,            only: endrun
       use shr_kind_mod,              only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,              only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,          only: const_get_index
       use ccpp_kinds,                only: kind_phys
       use cam_logfile,               only: iulog
@@ -227,6 +239,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,      only: is_read_from_file
       use ioFileMod,                 only: cam_get_file
       use cam_pio_utils,             only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_ddt2, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_ddt2,        only: phys_state
 
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -345,6 +342,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_ddt_array.F90 b/test/unit/sample_files/write_init_files/physics_inputs_ddt_array.F90
index 620eceed..c9c0b278 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_ddt_array.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_ddt_array.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,                   only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,                   only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                     only: kind_phys
-      use phys_vars_init_check_ddt_array, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_ddt_array, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod,      only: ccpp_constituent_prop_ptr_t
       use cam_logfile,                    only: iulog
       use physics_types_ddt_array,        only: ix_theta, phys_state
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,6 +170,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -219,7 +231,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,                 only: endrun
       use shr_kind_mod,                   only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,                   only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,                   only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,                   only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,               only: const_get_index
       use ccpp_kinds,                     only: kind_phys
       use cam_logfile,                    only: iulog
@@ -227,6 +239,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,           only: is_read_from_file
       use ioFileMod,                      only: cam_get_file
       use cam_pio_utils,                  only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod,      only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_ddt_array, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_ddt_array,        only: ix_theta, phys_state
 
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -345,6 +342,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_host_var.F90 b/test/unit/sample_files/write_init_files/physics_inputs_host_var.F90
index 34d18e84..9b4dc702 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_host_var.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_host_var.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,                  only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,                  only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                    only: kind_phys
-      use phys_vars_init_check_host_var, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_host_var, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod,     only: ccpp_constituent_prop_ptr_t
       use cam_logfile,                   only: iulog
       use physics_types_host_var,        only: slp
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -209,6 +167,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -216,7 +228,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,                only: endrun
       use shr_kind_mod,                  only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,                  only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,                  only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,                  only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,              only: const_get_index
       use ccpp_kinds,                    only: kind_phys
       use cam_logfile,                   only: iulog
@@ -224,6 +236,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,          only: is_read_from_file
       use ioFileMod,                     only: cam_get_file
       use cam_pio_utils,                 only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod,     only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_host_var, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_host_var,        only: slp
 
@@ -257,7 +270,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -296,25 +311,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -338,6 +335,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_mf.F90 b/test/unit/sample_files/write_init_files/physics_inputs_mf.F90
index 868c512b..7ccaf7ee 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_mf.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_mf.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,              only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                only: kind_phys
-      use phys_vars_init_check_mf,   only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_mf,   only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
       use cam_logfile,               only: iulog
       use ref_theta,                 only: theta
@@ -70,10 +70,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -134,51 +136,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -213,24 +171,79 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
-      use pio,                     only: file_desc_t, pio_nowrite
-      use cam_abortutils,          only: endrun
-      use shr_kind_mod,            only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
-      use physics_data,            only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,            only: ccpp_physics_suite_variables, cam_advected_constituents_array
-      use cam_constituents,        only: const_get_index
-      use ccpp_kinds,              only: kind_phys
-      use cam_logfile,             only: iulog
-      use spmd_utils,              only: masterproc
-      use phys_vars_init_check,    only: is_read_from_file
-      use ioFileMod,               only: cam_get_file
-      use cam_pio_utils,           only: cam_pio_openfile, cam_pio_closefile
-      use phys_vars_init_check_mf, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
-      use ref_theta,               only: theta
-      use physics_types_mf,        only: slp
+      use pio,                       only: file_desc_t, pio_nowrite
+      use cam_abortutils,            only: endrun
+      use shr_kind_mod,              only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
+      use physics_data,              only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
+      use cam_ccpp_cap,              only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
+      use cam_constituents,          only: const_get_index
+      use ccpp_kinds,                only: kind_phys
+      use cam_logfile,               only: iulog
+      use spmd_utils,                only: masterproc
+      use phys_vars_init_check,      only: is_read_from_file
+      use ioFileMod,                 only: cam_get_file
+      use cam_pio_utils,             only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
+      use phys_vars_init_check_mf,   only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use ref_theta,                 only: theta
+      use physics_types_mf,          only: slp
 
       ! Dummy arguments
       character(len=SHR_KIND_CL), intent(in) :: file_name
@@ -262,7 +275,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -301,25 +316,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -347,6 +344,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_no_horiz.F90 b/test/unit/sample_files/write_init_files/physics_inputs_no_horiz.F90
index 96453a7f..d238768e 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_no_horiz.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_no_horiz.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,                  only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,                  only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                    only: kind_phys
-      use phys_vars_init_check_no_horiz, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_no_horiz, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod,     only: ccpp_constituent_prop_ptr_t
       use cam_logfile,                   only: iulog
       use physics_types_no_horiz,        only: slp, theta
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,6 +170,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -219,7 +231,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,                only: endrun
       use shr_kind_mod,                  only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,                  only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,                  only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,                  only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,              only: const_get_index
       use ccpp_kinds,                    only: kind_phys
       use cam_logfile,                   only: iulog
@@ -227,6 +239,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,          only: is_read_from_file
       use ioFileMod,                     only: cam_get_file
       use cam_pio_utils,                 only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod,     only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_no_horiz, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_no_horiz,        only: slp, theta
 
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -344,6 +341,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_noreq.F90 b/test/unit/sample_files/write_init_files/physics_inputs_noreq.F90
index 2d532a63..52eb8cf9 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_noreq.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_noreq.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,               only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,               only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                 only: kind_phys
-      use phys_vars_init_check_noreq, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_noreq, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod,  only: ccpp_constituent_prop_ptr_t
       use cam_logfile,                only: iulog
 
@@ -68,10 +68,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -132,51 +134,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -205,6 +163,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -212,7 +224,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,             only: endrun
       use shr_kind_mod,               only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,               only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,               only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,               only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,           only: const_get_index
       use ccpp_kinds,                 only: kind_phys
       use cam_logfile,                only: iulog
@@ -220,6 +232,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,       only: is_read_from_file
       use ioFileMod,                  only: cam_get_file
       use cam_pio_utils,              only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod,  only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_noreq, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
 
       ! Dummy arguments
@@ -252,7 +265,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -291,25 +306,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -329,6 +326,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_param.F90 b/test/unit/sample_files/write_init_files/physics_inputs_param.F90
index 0136b24c..3cdfb21a 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_param.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_param.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,               only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,               only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                 only: kind_phys
-      use phys_vars_init_check_param, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_param, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod,  only: ccpp_constituent_prop_ptr_t
       use cam_logfile,                only: iulog
       use physics_types_param,        only: g, slp, theta
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -215,6 +173,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -222,7 +234,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,             only: endrun
       use shr_kind_mod,               only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,               only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,               only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,               only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,           only: const_get_index
       use ccpp_kinds,                 only: kind_phys
       use cam_logfile,                only: iulog
@@ -230,6 +242,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,       only: is_read_from_file
       use ioFileMod,                  only: cam_get_file
       use cam_pio_utils,              only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod,  only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_param, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_param,        only: g, slp, theta
 
@@ -263,7 +276,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -302,25 +317,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -351,6 +348,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_protect.F90 b/test/unit/sample_files/write_init_files/physics_inputs_protect.F90
index b5c6e5f4..c578c2fc 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_protect.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_protect.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,                 only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,                 only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                   only: kind_phys
-      use phys_vars_init_check_protect, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_protect, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod,    only: ccpp_constituent_prop_ptr_t
       use cam_logfile,                  only: iulog
       use physics_types_protected,      only: slp, theta
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,6 +170,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -219,7 +231,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,               only: endrun
       use shr_kind_mod,                 only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,                 only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,                 only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,                 only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,             only: const_get_index
       use ccpp_kinds,                   only: kind_phys
       use cam_logfile,                  only: iulog
@@ -227,6 +239,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,         only: is_read_from_file
       use ioFileMod,                    only: cam_get_file
       use cam_pio_utils,                only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod,    only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_protect, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_protected,      only: slp, theta
 
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -345,6 +342,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_scalar.F90 b/test/unit/sample_files/write_init_files/physics_inputs_scalar.F90
index 065fb36f..4159f127 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_scalar.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_scalar.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,                only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,                only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                  only: kind_phys
-      use phys_vars_init_check_scalar, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_scalar, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod,   only: ccpp_constituent_prop_ptr_t
       use cam_logfile,                 only: iulog
       use physics_types_scalar_var,    only: slp, theta
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,6 +170,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -219,7 +231,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,              only: endrun
       use shr_kind_mod,                only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,                only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,                only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,                only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,            only: const_get_index
       use ccpp_kinds,                  only: kind_phys
       use cam_logfile,                 only: iulog
@@ -227,6 +239,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,        only: is_read_from_file
       use ioFileMod,                   only: cam_get_file
       use cam_pio_utils,               only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod,   only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_scalar, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_scalar_var,    only: slp, theta
 
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -344,6 +341,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/sample_files/write_init_files/physics_inputs_simple.F90 b/test/unit/sample_files/write_init_files/physics_inputs_simple.F90
index f4eb298c..1b55d8a3 100644
--- a/test/unit/sample_files/write_init_files/physics_inputs_simple.F90
+++ b/test/unit/sample_files/write_init_files/physics_inputs_simple.F90
@@ -36,7 +36,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       use physics_data,                only: read_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
       use cam_ccpp_cap,                only: ccpp_physics_suite_variables, cam_constituents_array, cam_model_const_properties
       use ccpp_kinds,                  only: kind_phys
-      use phys_vars_init_check_simple, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
+      use phys_vars_init_check_simple, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len, is_initialized
       use ccpp_constituent_prop_mod,   only: ccpp_constituent_prop_ptr_t
       use cam_logfile,                 only: iulog
       use physics_types_simple,        only: slp, theta
@@ -69,10 +69,12 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
       character(len=2)           :: sep3            !String separator used to print err messages
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
       logical                    :: var_found       !Bool to determine if consituent found in data files
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
 
       ! Fields needed for getting default data value for constituents
       type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
       real(kind=kind_phys)                       :: constituent_default_value
+      real(kind=kind_phys)                       :: constituent_min_value
       integer                                    :: constituent_errflg
       character(len=512)                         :: constituent_errmsg
       logical                                    :: constituent_has_default
@@ -133,51 +135,7 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
                case (const_idx)
 
-                  ! If an index was found in the constituent hash table, then read in the data to that index of the constituent array
-
-                  var_found = .false.
-                  field_data_ptr => cam_constituents_array()
-
-                  ! Check if constituent standard name in registered SIMA standard names list:
-                  if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                     ! Find array index to extract correct input names:
-                     do n=1, phys_var_num
-                        if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                           const_input_idx = n
-                           exit
-                        end if
-                     end do
-                     call read_field(file, ccpp_required_data(req_idx), input_var_names(:,const_input_idx), 'lev', timestep,                           &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  else
-                     ! If not in standard names list, then just use constituent name as input file name:
-                     call read_field(file, ccpp_required_data(req_idx), [ccpp_required_data(req_idx)], 'lev', timestep,                                &
-                          field_data_ptr(:,:,constituent_idx), mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
-                  end if
-                  if(.not. var_found) then
-                     const_props => cam_model_const_properties()
-                     constituent_has_default = .false.
-                     call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
-                     if (constituent_errflg /= 0) then
-                        call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                     end if
-                     if (constituent_has_default) then
-                        call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
-                        if (constituent_errflg /= 0) then
-                           call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
-                        end if
-                        field_data_ptr(:,:,constituent_idx) = constituent_default_value
-                        if (masterproc) then
-                           write(iulog,*) 'Consitituent ', trim(ccpp_required_data(req_idx)), ' initialized to default value: ',                       &
-                                constituent_default_value
-                        end if
-                     else
-                        field_data_ptr(:,:,constituent_idx) = 0._kind_phys
-                        if (masterproc) then
-                           write(iulog,*) 'Constituent ', trim(ccpp_required_data(req_idx)), ' default value not configured.  Setting to 0.'
-                        end if
-                     end if
-                  end if
+                  ! If an index was found in the constituent hash table, then do nothing, this will be handled later
 
                case default
 
@@ -212,6 +170,60 @@ subroutine physics_read_data(file, suite_names, timestep, read_initialized_varia
 
       end do !CCPP suites
 
+      ! Read in constituent variables if not using init variables
+      field_data_ptr => cam_constituents_array()
+      const_props => cam_model_const_properties()
+
+      ! Iterate over all registered constituents
+      do constituent_idx = 1, size(const_props)
+         var_found = .false.
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == trim(std_name))) then
+            ! Don't read the variable in if it's already initialized
+            if (is_initialized(std_name)) then
+               cycle
+            end if
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call read_field(file, std_name, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                  &
+                 mark_as_read=.false., error_on_not_found=.false., var_found=var_found)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call read_field(file, std_name, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), mark_as_read=.false.,                    &
+                 error_on_not_found=.false., var_found=var_found)
+         end if
+         if(.not. var_found) then
+            constituent_has_default = .false.
+            call const_props(constituent_idx)%has_default(constituent_has_default, constituent_errflg, constituent_errmsg)
+            if (constituent_errflg /= 0) then
+               call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+            end if
+            if (constituent_has_default) then
+               call const_props(constituent_idx)%default_value(constituent_default_value, constituent_errflg, constituent_errmsg)
+               if (constituent_errflg /= 0) then
+                  call endrun(constituent_errmsg, file=__FILE__, line=__LINE__)
+               end if
+               field_data_ptr(:,:,constituent_idx) = constituent_default_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' initialized to default value: ', constituent_default_value
+               end if
+            else
+               ! Intialize to constituent's configured minimum value
+               call const_props(constituent_idx)%minimum(constituent_min_value, constituent_errflg, constituent_errmsg)
+               field_data_ptr(:,:,constituent_idx) = constituent_min_value
+               if (masterproc) then
+                  write(iulog,*) 'Constituent ', trim(std_name), ' default value not configured.  Setting to 0.'
+               end if
+            end if
+         end if
+      end do
+
    end subroutine physics_read_data
 
    subroutine physics_check_data(file_name, suite_names, timestep, min_difference, min_relative_value)
@@ -219,7 +231,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use cam_abortutils,              only: endrun
       use shr_kind_mod,                only: SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX
       use physics_data,                only: check_field, find_input_name_idx, no_exist_idx, init_mark_idx, prot_no_init_idx, const_idx
-      use cam_ccpp_cap,                only: ccpp_physics_suite_variables, cam_advected_constituents_array
+      use cam_ccpp_cap,                only: ccpp_physics_suite_variables, cam_advected_constituents_array, cam_model_const_properties
       use cam_constituents,            only: const_get_index
       use ccpp_kinds,                  only: kind_phys
       use cam_logfile,                 only: iulog
@@ -227,6 +239,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       use phys_vars_init_check,        only: is_read_from_file
       use ioFileMod,                   only: cam_get_file
       use cam_pio_utils,               only: cam_pio_openfile, cam_pio_closefile
+      use ccpp_constituent_prop_mod,   only: ccpp_constituent_prop_ptr_t
       use phys_vars_init_check_simple, only: phys_var_num, phys_var_stdnames, input_var_names, std_name_len
       use physics_types_simple,        only: slp, theta
 
@@ -260,7 +273,9 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
       logical                    :: file_found
       logical                    :: is_first
       logical                    :: is_read
+      character(len=std_name_len) :: std_name       !Variable to hold constiutent standard name
       real(kind=kind_phys), pointer :: field_data_ptr(:,:,:)
+      type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
 
       ! Initalize missing and non-initialized variables strings:
       missing_required_vars = ' '
@@ -299,25 +314,7 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
             ! First check if the required variable is a constituent:
             call const_get_index(ccpp_required_data(req_idx), constituent_idx, abort=.false., warning=.false.)
             if (constituent_idx > -1) then
-               ! The required variable is a constituent. Call check variable routine on the relevant index of the constituent array
-               field_data_ptr => cam_advected_constituents_array()
-
-               ! Check if constituent standard name in registered SIMA standard names list:
-               if(any(phys_var_stdnames == ccpp_required_data(req_idx))) then
-                  ! Find array index to extract correct input names:
-                  do n=1, phys_var_num
-                     if(trim(phys_var_stdnames(n)) == trim(ccpp_required_data(req_idx))) then
-                        const_input_idx = n
-                        exit
-                     end if
-                  end do
-                  call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx),                     &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               else
-                  ! If not in standard names list, then just use constituent name as input file name:
-                  call check_field(file, [ccpp_required_data(req_idx)], 'lev', timestep, field_data_ptr(:,:,constituent_idx),                          &
-                       ccpp_required_data(req_idx), min_difference, min_relative_value, is_first)
-               end if
+               cycle
             else
                ! The required variable is not a constituent. Check if the variable was read from a file
                ! Find IC file input name array index for required variable:
@@ -345,6 +342,29 @@ subroutine physics_check_data(file_name, suite_names, timestep, min_difference,
 
       end do !CCPP suites
 
+      ! Check constituent variables
+      field_data_ptr => cam_advected_constituents_array()
+      const_props => cam_model_const_properties()
+
+      do constituent_idx = 1, size(const_props)
+         ! Check if constituent standard name in registered SIMA standard names list:
+         call const_props(constituent_idx)%standard_name(std_name)
+         if(any(phys_var_stdnames == std_name)) then
+            ! Find array index to extract correct input names:
+            do n=1, phys_var_num
+               if(trim(phys_var_stdnames(n)) == trim(std_name)) then
+                  const_input_idx = n
+                  exit
+               end if
+            end do
+            call check_field(file, input_var_names(:,const_input_idx), 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name,                 &
+                 min_difference, min_relative_value, is_first)
+         else
+            ! If not in standard names list, then just use constituent name as input file name:
+            call check_field(file, [std_name], 'lev', timestep, field_data_ptr(:,:,constituent_idx), std_name, min_difference, min_relative_value,     &
+                 is_first)
+         end if
+      end do
       ! Close check file:
       call cam_pio_closefile(file)
       deallocate(file)
diff --git a/test/unit/test_build_cache.py b/test/unit/test_build_cache.py
index ed17d094..39dc59d2 100644
--- a/test/unit/test_build_cache.py
+++ b/test/unit/test_build_cache.py
@@ -425,9 +425,11 @@ def test_update_registry(self):
         ic_names = {"Only_had_a": ["heart", "brain"]}
         dycore = "banana"
 
+        constituents = ['cnst_1', 'cnst_2']
+
         #Update registry fields:
         test_cache.update_registry(tmp_test_reg, [tmp_test_reg],
-                                   dycore, [tmp_test_reg], ic_names)
+                                   dycore, [tmp_test_reg], ic_names, constituents)
 
         #Write updated fields to build cache file:
         test_cache.write()
diff --git a/test/unit/test_cam_autogen.py b/test/unit/test_cam_autogen.py
index 58f54daa..4a786aab 100644
--- a/test/unit/test_cam_autogen.py
+++ b/test/unit/test_cam_autogen.py
@@ -158,6 +158,10 @@ def ic_names(self):
 
         return {}
 
+    def constituents(self):
+        """Fake version of 'constituents' property."""
+        return []
+
     # pylint: enable=no-self-use
     # pylint: enable=unused-argument
 
@@ -515,7 +519,7 @@ def test_generate_registry(self):
         test_data_search = [os.path.join(_CAM_ROOT_DIR, "src", "data")]
 
         #Set expected output tuple:
-        expected_results = (f'{self.test_bldroot}'+os.sep+'cam_registry', False, [], {})
+        expected_results = (f'{self.test_bldroot}'+os.sep+'cam_registry', False, [], {}, [])
 
         #Run registry generation function:
         gen_results = generate_registry(test_data_search, self.test_cache, _CAM_ROOT_DIR,
@@ -670,7 +674,7 @@ def test_generate_init_routines(self):
 
         #Run init routines generation function:
         gen_path = generate_init_routines(self.test_cache, self.test_bldroot, False, False,
-                                          self.test_src_mods_dir, self.fort_indent, None, {})
+                                          self.test_src_mods_dir, self.fort_indent, None, {}, [])
 
         #Check that the output path matches what is expected:
         self.assertEqual(gen_path, expected_path)
diff --git a/test/unit/test_registry.py b/test/unit/test_registry.py
index 0b6bb6c6..6fff5360 100644
--- a/test/unit/test_registry.py
+++ b/test/unit/test_registry.py
@@ -95,7 +95,7 @@ def test_good_simple_registry(self):
         out_meta = os.path.join(_TMP_DIR, out_source_name + '.meta')
         remove_files([out_source, out_meta])
         # Run test
-        retcode, files, _ = gen_registry(filename, 'fv', _TMP_DIR, 2,
+        retcode, files, _, _ = gen_registry(filename, 'fv', _TMP_DIR, 2,
                                          _SRC_MOD_DIR, _CAM_ROOT,
                                          loglevel=logging.ERROR,
                                          error_on_no_validate=True)
@@ -156,7 +156,7 @@ def test_good_ddt_registry(self):
             out_meta = os.path.join(_TMP_DIR, out_meta_name)
             remove_files([out_source, out_meta])
             # Run dycore
-            retcode, files, _ = gen_registry(filename, dycore, _TMP_DIR, 2,
+            retcode, files, _, _ = gen_registry(filename, dycore, _TMP_DIR, 2,
                                              _SRC_MOD_DIR, _CAM_ROOT,
                                              loglevel=logging.ERROR,
                                              error_on_no_validate=True)
@@ -203,7 +203,7 @@ def test_good_ddt_registry2(self):
         out_meta = os.path.join(_TMP_DIR, out_meta_name)
         remove_files([out_source, out_meta])
         # Run dycore
-        retcode, files, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
+        retcode, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
                                          _SRC_MOD_DIR, _CAM_ROOT,
                                          loglevel=logging.ERROR,
                                          error_on_no_validate=True)
@@ -243,7 +243,7 @@ def test_good_array(self):
         out_meta = os.path.join(_TMP_DIR, out_meta_name)
         remove_files([out_source, out_meta])
         # Run dycore
-        retcode, files, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
+        retcode, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
                                          _SRC_MOD_DIR, _CAM_ROOT,
                                          loglevel=logging.ERROR,
                                          error_on_no_validate=True)
@@ -281,7 +281,7 @@ def test_good_metadata_file_registry(self):
         out_meta = os.path.join(_TMP_DIR, out_name + '.meta')
         remove_files([out_source, out_meta])
         # generate registry
-        retcode, files, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
+        retcode, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
                                          _SRC_MOD_DIR, _CAM_ROOT,
                                          loglevel=logging.ERROR,
                                          error_on_no_validate=True)
@@ -335,7 +335,7 @@ def test_diff_src_root_metadata_file_registry(self):
         shutil.copy(meta_file, tmp_src_dir)
 
         # Generate registry
-        retcode, files, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
+        retcode, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
                                          _SRC_MOD_DIR, _TMP_DIR,
                                          loglevel=logging.ERROR,
                                          error_on_no_validate=True)
@@ -392,7 +392,7 @@ def test_SourceMods_metadata_file_registry(self):
         shutil.copy(meta_file, source_mod_file)
 
         # Generate registry
-        retcode, files, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
+        retcode, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
                                          tmp_src_dir, _CAM_ROOT,
                                          loglevel=logging.ERROR,
                                          error_on_no_validate=True)
@@ -443,7 +443,7 @@ def test_good_complete_registry(self):
         remove_files([out_source, out_meta])
 
         # Run test
-        retcode, files, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
+        retcode, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 2,
                                          _SRC_MOD_DIR, _CAM_ROOT,
                                          loglevel=logging.ERROR,
                                          error_on_no_validate=True)
@@ -550,7 +550,7 @@ def test_parameter(self):
         # End for
         tree.write(filename)
         # Run test
-        retcode, files, _ = gen_registry(filename, 'eul', _TMP_DIR, 2,
+        retcode, files, _, _ = gen_registry(filename, 'eul', _TMP_DIR, 2,
                                          _SRC_MOD_DIR, _CAM_ROOT,
                                          loglevel=logging.ERROR,
                                          error_on_no_validate=True)
diff --git a/test/unit/test_write_init_files.py b/test/unit/test_write_init_files.py
index d0736ee0..903df86d 100644
--- a/test/unit/test_write_init_files.py
+++ b/test/unit/test_write_init_files.py
@@ -175,7 +175,7 @@ def test_simple_reg_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -238,7 +238,7 @@ def test_simple_reg_constituent_write_init(self):
                       check_init_out, phys_input_out])
 
         # Generate registry files:
-        _, _, ic_names = gen_registry(filename, 'se', _TMP_DIR, 3,
+        _, _, ic_names, constituents = gen_registry(filename, 'se', _TMP_DIR, 3,
                                       _SRC_MOD_DIR, _CAM_ROOT,
                                       loglevel=logging.ERROR,
                                       error_on_no_validate=True)
@@ -258,7 +258,7 @@ def test_simple_reg_constituent_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, ic_names, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, ic_names, constituents, _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -340,7 +340,7 @@ def test_no_reqvar_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -403,7 +403,7 @@ def test_protected_reg_write_init(self):
                       check_init_out, phys_input_out])
 
         # Generate registry files:
-        _, files, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
+        _, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
                                    _SRC_MOD_DIR, _CAM_ROOT,
                                    loglevel=logging.ERROR,
                                    error_on_no_validate=True)
@@ -423,7 +423,7 @@ def test_protected_reg_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -507,7 +507,7 @@ def test_host_input_var_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [],  _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -572,7 +572,7 @@ def test_no_horiz_var_write_init(self):
         remove_files([out_source, out_meta, cap_datafile, check_init_out, phys_input_out])
 
         # Generate registry files:
-        _, files, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
+        _, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
                                    _SRC_MOD_DIR, _CAM_ROOT,
                                    loglevel=logging.ERROR,
                                    error_on_no_validate=True)
@@ -592,7 +592,7 @@ def test_no_horiz_var_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Run test
-        _ = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        _ = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                         find_file, _INC_SEARCH_DIRS,
                                         3, logger,
                                         phys_check_filename=vic_name,
@@ -647,7 +647,7 @@ def test_scalar_var_write_init(self):
                       check_init_out, phys_input_out])
 
         # Generate registry files:
-        _, files, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
+        _, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
                                    _SRC_MOD_DIR, _CAM_ROOT,
                                    loglevel=logging.ERROR,
                                    error_on_no_validate=True)
@@ -667,7 +667,7 @@ def test_scalar_var_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Run test
-        _ = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        _ = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                         find_file, _INC_SEARCH_DIRS,
                                         3, logger,
                                         phys_check_filename=vic_name,
@@ -722,7 +722,7 @@ def test_4d_var_write_init(self):
                       check_init_out, phys_input_out])
 
         # Generate registry files:
-        _, files, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
+        _, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
                                    _SRC_MOD_DIR, _CAM_ROOT,
                                    loglevel=logging.ERROR,
                                    error_on_no_validate=True)
@@ -741,7 +741,7 @@ def test_4d_var_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Run test
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -815,7 +815,7 @@ def test_ddt_reg_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -878,7 +878,7 @@ def test_ddt2_reg_write_init(self):
                       check_init_out, phys_input_out])
 
         # Generate registry files:
-        _, files, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
+        _, files, _, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
                                    _SRC_MOD_DIR, _CAM_ROOT,
                                    loglevel=logging.ERROR,
                                    error_on_no_validate=True)
@@ -897,7 +897,7 @@ def test_ddt2_reg_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [],  _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -959,7 +959,7 @@ def test_ddt_array_reg_write_init(self):
                       check_init_out, phys_input_out])
 
         # Generate registry files:
-        _, _, ic_names = gen_registry(filename, 'se', _TMP_DIR, 3,
+        _, _, ic_names, _ = gen_registry(filename, 'se', _TMP_DIR, 3,
                          _SRC_MOD_DIR, _CAM_ROOT,
                          loglevel=logging.ERROR,
                          error_on_no_validate=True)
@@ -978,7 +978,7 @@ def test_ddt_array_reg_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, ic_names, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, ic_names, [], _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -1059,7 +1059,7 @@ def test_meta_file_reg_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -1140,7 +1140,7 @@ def test_parameter_reg_write_init(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Generate physics initialization files:
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,
@@ -1224,7 +1224,7 @@ def test_bad_vertical_dimension(self):
         cap_database = capgen(run_env, return_db=True)
 
         # Run test
-        retmsg = write_init.write_init_files(cap_database, {}, _TMP_DIR,
+        retmsg = write_init.write_init_files(cap_database, {}, [], _TMP_DIR,
                                              find_file, _INC_SEARCH_DIRS,
                                              3, logger,
                                              phys_check_filename=vic_name,