diff --git a/modules/aws/networking/tgw-vpc-attachment/README.md b/modules/aws/networking/tgw-vpc-attachment/README.md
index 0b11263..e925929 100644
--- a/modules/aws/networking/tgw-vpc-attachment/README.md
+++ b/modules/aws/networking/tgw-vpc-attachment/README.md
@@ -38,6 +38,7 @@ No requirements.
 |------|-------------|------|---------|:--------:|
 | <a name="input_attachment_subnet_ids"></a> [attachment\_subnet\_ids](#input\_attachment\_subnet\_ids) | A map of dedicated /28 subnet IDs for each AZ. The keys must match the AZ names provided in `azs`. | `map(string)` | n/a | yes |
 | <a name="input_azs"></a> [azs](#input\_azs) | List of Availability Zones for which the dedicated /28 subnets exist. The order of the AZs determines the order of subnets used in the attachment. | `list(string)` | n/a | yes |
+| <a name="input_transit_gateway_default_route_table_propagation"></a> [transit\_gateway\_default\_route\_table\_propagation](#input\_transit\_gateway\_default\_route\_table\_propagation) | (Optional) Boolean whether the VPC Attachment should propagate routes with the EC2 Transit Gateway propagation default route table. | `bool` | `true` | no |
 | <a name="input_transit_gateway_id"></a> [transit\_gateway\_id](#input\_transit\_gateway\_id) | The ID of the Transit Gateway. | `string` | n/a | yes |
 | <a name="input_vpc_id"></a> [vpc\_id](#input\_vpc\_id) | The ID of the VPC to attach. | `string` | n/a | yes |
 ## Outputs
diff --git a/modules/aws/networking/tgw-vpc-attachment/main.tf b/modules/aws/networking/tgw-vpc-attachment/main.tf
index 184d038..91437e9 100644
--- a/modules/aws/networking/tgw-vpc-attachment/main.tf
+++ b/modules/aws/networking/tgw-vpc-attachment/main.tf
@@ -7,8 +7,9 @@ locals {
 }
 
 resource "aws_ec2_transit_gateway_vpc_attachment" "twg_vpc" {
-  transit_gateway_id = var.transit_gateway_id
-  vpc_id             = var.vpc_id
-  subnet_ids         = local.ordered_attachment_subnet_ids
+  transit_gateway_id                              = var.transit_gateway_id
+  vpc_id                                          = var.vpc_id
+  subnet_ids                                      = local.ordered_attachment_subnet_ids
+  transit_gateway_default_route_table_propagation = var.transit_gateway_default_route_table_propagation
 
 }
diff --git a/modules/aws/networking/tgw-vpc-attachment/variables.tf b/modules/aws/networking/tgw-vpc-attachment/variables.tf
index e1eba2a..0730058 100644
--- a/modules/aws/networking/tgw-vpc-attachment/variables.tf
+++ b/modules/aws/networking/tgw-vpc-attachment/variables.tf
@@ -25,3 +25,8 @@ variable "attachment_subnet_ids" {
   # }
 }
 
+variable "transit_gateway_default_route_table_propagation" {
+  description = "(Optional) Boolean whether the VPC Attachment should propagate routes with the EC2 Transit Gateway propagation default route table."
+  type        = bool
+  default     = true
+}