diff --git a/mmv1/products/bigqueryreservation/CapacityCommitment.yaml b/mmv1/products/bigqueryreservation/CapacityCommitment.yaml
index 17649a1bfcff..bd51ff262e37 100644
--- a/mmv1/products/bigqueryreservation/CapacityCommitment.yaml
+++ b/mmv1/products/bigqueryreservation/CapacityCommitment.yaml
@@ -31,6 +31,8 @@ import_format:
   [
     'projects/{{project}}/locations/{{location}}/capacityCommitments/{{capacity_commitment_id}}',
   ]
+custom_code: !ruby/object:Provider::Terraform::CustomCode
+  constants: templates/terraform/constants/bigquery_reservation_capacity_commitment.go.erb
 examples:
   - !ruby/object:Provider::Terraform::Examples
     name: 'bigquery_reservation_capacity_commitment_basic'
@@ -81,6 +83,7 @@ properties:
     required: true
     description: |
       Capacity commitment plan. Valid values are at https://cloud.google.com/bigquery/docs/reference/reservations/rpc/google.cloud.bigquery.reservation.v1#commitmentplan
+    diff_suppress_func: bigqueryReservationCapacityCommitmentPlanDiffSuppressFunc
   - !ruby/object:Api::Type::String
     name: 'state'
     output: true
diff --git a/mmv1/templates/terraform/constants/bigquery_reservation_capacity_commitment.go.erb b/mmv1/templates/terraform/constants/bigquery_reservation_capacity_commitment.go.erb
new file mode 100644
index 000000000000..8af8fa7e5755
--- /dev/null
+++ b/mmv1/templates/terraform/constants/bigquery_reservation_capacity_commitment.go.erb
@@ -0,0 +1,6 @@
+func bigqueryReservationCapacityCommitmentPlanDiffSuppressFunc(_, old, new string, _ *schema.ResourceData) bool {
+	if (old == "FLEX" || old == "MONTHLY" || old == "ANNUAL") && new == old+"_FLAT_RATE" {
+		return true
+	}
+	return false
+}