diff --git a/mmv1/products/bigqueryreservation/ReservationAssignment.yaml b/mmv1/products/bigqueryreservation/ReservationAssignment.yaml
index 2c0494b0526f..764ec22596e0 100644
--- a/mmv1/products/bigqueryreservation/ReservationAssignment.yaml
+++ b/mmv1/products/bigqueryreservation/ReservationAssignment.yaml
@@ -41,6 +41,9 @@ nested_query:
   modify_by_patch: false
 custom_code:
   pre_create: 'templates/terraform/pre_create/bigquery_reservation_assignment.go.tmpl'
+  post_read: 'templates/terraform/post_read/bigquery_reservation_assignment.go.tmpl'
+  constants: 'templates/terraform/constants/bigquery_reservation_assignment.go.tmpl'
+  test_check_destroy: 'templates/terraform/custom_check_destroy/bigquery_reservation_assignment.go.tmpl'
 legacy_long_form_project: true
 examples:
   - name: 'bigquery_reservation_assignment_basic'
@@ -71,6 +74,7 @@ parameters:
     immutable: true
     resource: 'reservation'
     imports: 'name'
+    diff_suppress_func: 'bigqueryReservationAssignmentReservationDiffSuppressFunc'
 properties:
   - name: 'name'
     type: String
diff --git a/mmv1/templates/terraform/constants/bigquery_reservation_assignment.go.tmpl b/mmv1/templates/terraform/constants/bigquery_reservation_assignment.go.tmpl
new file mode 100644
index 000000000000..f79944e11a30
--- /dev/null
+++ b/mmv1/templates/terraform/constants/bigquery_reservation_assignment.go.tmpl
@@ -0,0 +1,10 @@
+func bigqueryReservationAssignmentReservationDiffSuppressFunc(k, old, new string, d *schema.ResourceData) bool {
+	oldParts := strings.Split(old, "/")
+	newParts := strings.Split(new, "/")
+
+	if len(oldParts) == 1 || len(newParts) == 1 {
+		return tpgresource.GetResourceNameFromSelfLink(old) == tpgresource.GetResourceNameFromSelfLink(new)
+	}
+
+	return tpgresource.CompareSelfLinkOrResourceName(k, old, new, d)
+}
diff --git a/mmv1/templates/terraform/custom_check_destroy/bigquery_reservation_assignment.go.tmpl b/mmv1/templates/terraform/custom_check_destroy/bigquery_reservation_assignment.go.tmpl
new file mode 100644
index 000000000000..53060bbba7da
--- /dev/null
+++ b/mmv1/templates/terraform/custom_check_destroy/bigquery_reservation_assignment.go.tmpl
@@ -0,0 +1,62 @@
+config := acctest.GoogleProviderConfig(t)
+url, err := tpgresource.ReplaceVarsForTest(config, rs, transport_tpg.BaseUrl(bigqueryreservation.Product, config)+"projects/{{"{{"}}project{{"}}"}}/locations/{{"{{"}}location{{"}}"}}/reservations/{{"{{"}}reservation{{"}}"}}/assignments")
+if err != nil {
+	return err
+}
+
+billingProject := ""
+
+if config.BillingProject != "" {
+	billingProject = config.BillingProject
+}
+
+res, err := transport_tpg.SendRequest(transport_tpg.SendRequestOptions{
+	Config:    config,
+	Method:    "GET",
+	Project:   billingProject,
+	RawURL:    url,
+	UserAgent: config.UserAgent,
+})
+if err != nil {
+	if transport_tpg.IsGoogleApiErrorWithCode(err, 404) {
+		continue
+	}
+	return err
+}
+
+v, ok := res["assignments"]
+if !ok || v == nil {
+	continue
+}
+
+var items []interface{}
+switch list := v.(type) {
+case []interface{}:
+	items = list
+case map[string]interface{}:
+	items = []interface{}{list}
+default:
+	return fmt.Errorf("expected list or map for assignments in CheckDestroy")
+}
+
+expectedName := tpgresource.GetResourceNameFromSelfLink(rs.Primary.ID)
+found := false
+for _, itemRaw := range items {
+	if itemRaw == nil {
+		continue
+	}
+	item := itemRaw.(map[string]interface{})
+	nameRaw, ok := item["name"].(string)
+	if !ok {
+		continue
+	}
+	itemName := tpgresource.GetResourceNameFromSelfLink(nameRaw)
+	if itemName == expectedName {
+		found = true
+		break
+	}
+}
+
+if found {
+	return fmt.Errorf("BigqueryReservationReservationAssignment %q still exists at %s", expectedName, url)
+}
diff --git a/mmv1/templates/terraform/post_read/bigquery_reservation_assignment.go.tmpl b/mmv1/templates/terraform/post_read/bigquery_reservation_assignment.go.tmpl
new file mode 100644
index 000000000000..2a1d3b881d46
--- /dev/null
+++ b/mmv1/templates/terraform/post_read/bigquery_reservation_assignment.go.tmpl
@@ -0,0 +1,20 @@
+if reservationVal, ok := d.GetOk("reservation"); ok {
+	reservation := reservationVal.(string)
+	if !strings.Contains(reservation, "/") && reservation != "" {
+		if project, err := tpgresource.GetProject(d, config); err == nil {
+			project = strings.TrimPrefix(project, "projects/")
+			location := d.Get("location").(string)
+			if location == "" {
+				idParts := strings.Split(d.Id(), "/")
+				if len(idParts) >= 4 && idParts[2] == "locations" {
+					location = idParts[3]
+				}
+			}
+			if location != "" {
+				if err := d.Set("reservation", fmt.Sprintf("projects/%s/locations/%s/reservations/%s", project, location, reservation)); err != nil {
+					return fmt.Errorf("Error setting normalized reservation: %s", err)
+				}
+			}
+		}
+	}
+}
diff --git a/mmv1/third_party/terraform/services/bigqueryreservation/resource_bigquery_reservation_assignment_test.go b/mmv1/third_party/terraform/services/bigqueryreservation/resource_bigquery_reservation_assignment_test.go
index 860ea46f7fd8..e7e73981ea33 100644
--- a/mmv1/third_party/terraform/services/bigqueryreservation/resource_bigquery_reservation_assignment_test.go
+++ b/mmv1/third_party/terraform/services/bigqueryreservation/resource_bigquery_reservation_assignment_test.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
 	"github.com/hashicorp/terraform-provider-google/google/acctest"
+	"github.com/hashicorp/terraform-provider-google/google/envvar"
 	_ "github.com/hashicorp/terraform-provider-google/google/services/bigqueryreservation"
 )
 
@@ -44,3 +45,57 @@ resource "google_bigquery_reservation_assignment" "test" {
 }
 `, context)
 }
+
+func TestAccBigqueryReservationReservationAssignment_customSymmetricReservationDiffSuppress(t *testing.T) {
+	t.Parallel()
+
+	randomSuffix := acctest.RandString(t, 10)
+
+	context := map[string]interface{}{
+		"project":          envvar.GetTestProjectFromEnv(),
+		"reservation_name": "tf-test-example-res-" + randomSuffix,
+		"random_suffix":    randomSuffix,
+	}
+
+	acctest.VcrTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.AccTestPreCheck(t) },
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		CheckDestroy:             testAccCheckBigqueryReservationReservationAssignmentDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccBigqueryReservationReservationAssignment_customSymmetricReservationDiffSuppress(context),
+			},
+			{
+				ResourceName:            "google_bigquery_reservation_assignment.assignment",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"location"}, // Verify reservation is NOT ignored and passes verification!
+			},
+			{
+				ResourceName:       "google_bigquery_reservation_assignment.assignment",
+				RefreshState:       true,
+				ExpectNonEmptyPlan: false, // Verify plan is clean post-import!
+				ImportStateKind:    resource.ImportBlockWithResourceIdentity,
+			},
+		},
+	})
+}
+
+func testAccBigqueryReservationReservationAssignment_customSymmetricReservationDiffSuppress(context map[string]interface{}) string {
+	return acctest.Nprintf(`
+resource "google_bigquery_reservation" "basic" {
+  name  = "%{reservation_name}"
+  project = "%{project}"
+  location = "us-central1"
+  slot_capacity = 0
+  ignore_idle_slots = false
+}
+
+resource "google_bigquery_reservation_assignment" "assignment" {
+  assignee  = "projects/%{project}"
+  job_type = "PIPELINE"
+  reservation = google_bigquery_reservation.basic.id
+  location = "us-central1"
+}
+`, context)
+}
diff --git a/mmv1/third_party/terraform/tpgresource/resource_test_utils.go b/mmv1/third_party/terraform/tpgresource/resource_test_utils.go
index a15deba3c94d..2b50c0f3f0f0 100644
--- a/mmv1/third_party/terraform/tpgresource/resource_test_utils.go
+++ b/mmv1/third_party/terraform/tpgresource/resource_test_utils.go
@@ -180,6 +180,14 @@ func ReplaceVarsForTest(config *transport_tpg.Config, rs *terraform.ResourceStat
 		}
 
 		if v, ok := rs.Primary.Attributes[m]; ok {
+			if strings.Count(v, "/") >= 3 &&
+				!strings.Contains(m, "parent") &&
+				m != "project" &&
+				m != "location" &&
+				m != "region" &&
+				m != "zone" {
+				return GetResourceNameFromSelfLink(v)
+			}
 			return v
 		}