diff --git a/vpc-transit-gateway-association/self/README.md b/vpc-transit-gateway-association/self/README.md
index b377a4e..d1a26dc 100644
--- a/vpc-transit-gateway-association/self/README.md
+++ b/vpc-transit-gateway-association/self/README.md
@@ -128,3 +128,4 @@ module "vpc_tgw_self" {
 | <a name="output_map_route_tables_self"></a> [map\_route\_tables\_self](#output\_map\_route\_tables\_self) | Transit Gateway route tables map (VRF:id) self (this region) |
 | <a name="output_route_tables_peer"></a> [route\_tables\_peer](#output\_route\_tables\_peer) | Transit Gateway route tables peer (other region) |
 | <a name="output_route_tables_self"></a> [route\_tables\_self](#output\_route\_tables\_self) | Transit Gateway route tables self (this region) |
+| <a name="output_vpc_attachment_id"></a> [vpc\_attachment\_id](#output\_vpc\_attachment\_id) | Transit Gateway VPC Attachment ID for this VPC |
diff --git a/vpc-transit-gateway-association/self/associate.tf b/vpc-transit-gateway-association/self/associate.tf
index 6a8fdad..3f4965c 100644
--- a/vpc-transit-gateway-association/self/associate.tf
+++ b/vpc-transit-gateway-association/self/associate.tf
@@ -21,6 +21,11 @@ resource "aws_ec2_transit_gateway_vpc_attachment" "vpc_attachment" {
   )
 }
 
+output "vpc_attachment_id" {
+  description = "Transit Gateway VPC Attachment ID for this VPC"
+  value       = aws_ec2_transit_gateway_vpc_attachment.vpc_attachment.id
+}
+
 #---
 # assocaite this vpc to route table in self (my region, network account)
 #---