diff --git a/google/cloud/network_management_v1/services/reachability_service/client.py b/google/cloud/network_management_v1/services/reachability_service/client.py
index 0d55707..ae1ce0b 100644
--- a/google/cloud/network_management_v1/services/reachability_service/client.py
+++ b/google/cloud/network_management_v1/services/reachability_service/client.py
@@ -362,6 +362,10 @@ def __init__(
                 client_cert_source_for_mtls=client_cert_source_func,
                 quota_project_id=client_options.quota_project_id,
                 client_info=client_info,
+                always_use_jwt_access=(
+                    Transport == type(self).get_transport_class("grpc")
+                    or Transport == type(self).get_transport_class("grpc_asyncio")
+                ),
             )
 
     def list_connectivity_tests(
diff --git a/tests/unit/gapic/network_management_v1/test_reachability_service.py b/tests/unit/gapic/network_management_v1/test_reachability_service.py
index 385d6ca..54b9adb 100644
--- a/tests/unit/gapic/network_management_v1/test_reachability_service.py
+++ b/tests/unit/gapic/network_management_v1/test_reachability_service.py
@@ -133,18 +133,6 @@ def test_reachability_service_client_from_service_account_info(client_class):
         assert client.transport._host == "networkmanagement.googleapis.com:443"
 
 
-@pytest.mark.parametrize(
-    "client_class", [ReachabilityServiceClient, ReachabilityServiceAsyncClient,]
-)
-def test_reachability_service_client_service_account_always_use_jwt(client_class):
-    with mock.patch.object(
-        service_account.Credentials, "with_always_use_jwt_access", create=True
-    ) as use_jwt:
-        creds = service_account.Credentials(None, None, None)
-        client = client_class(credentials=creds)
-        use_jwt.assert_not_called()
-
-
 @pytest.mark.parametrize(
     "transport_class,transport_name",
     [
@@ -152,7 +140,7 @@ def test_reachability_service_client_service_account_always_use_jwt(client_class
         (transports.ReachabilityServiceGrpcAsyncIOTransport, "grpc_asyncio"),
     ],
 )
-def test_reachability_service_client_service_account_always_use_jwt_true(
+def test_reachability_service_client_service_account_always_use_jwt(
     transport_class, transport_name
 ):
     with mock.patch.object(
@@ -162,6 +150,13 @@ def test_reachability_service_client_service_account_always_use_jwt_true(
         transport = transport_class(credentials=creds, always_use_jwt_access=True)
         use_jwt.assert_called_once_with(True)
 
+    with mock.patch.object(
+        service_account.Credentials, "with_always_use_jwt_access", create=True
+    ) as use_jwt:
+        creds = service_account.Credentials(None, None, None)
+        transport = transport_class(credentials=creds, always_use_jwt_access=False)
+        use_jwt.assert_not_called()
+
 
 @pytest.mark.parametrize(
     "client_class", [ReachabilityServiceClient, ReachabilityServiceAsyncClient,]
@@ -246,6 +241,7 @@ def test_reachability_service_client_client_options(
             client_cert_source_for_mtls=None,
             quota_project_id=None,
             client_info=transports.base.DEFAULT_CLIENT_INFO,
+            always_use_jwt_access=True,
         )
 
     # Check the case api_endpoint is not provided and GOOGLE_API_USE_MTLS_ENDPOINT is
@@ -262,6 +258,7 @@ def test_reachability_service_client_client_options(
                 client_cert_source_for_mtls=None,
                 quota_project_id=None,
                 client_info=transports.base.DEFAULT_CLIENT_INFO,
+                always_use_jwt_access=True,
             )
 
     # Check the case api_endpoint is not provided and GOOGLE_API_USE_MTLS_ENDPOINT is
@@ -278,6 +275,7 @@ def test_reachability_service_client_client_options(
                 client_cert_source_for_mtls=None,
                 quota_project_id=None,
                 client_info=transports.base.DEFAULT_CLIENT_INFO,
+                always_use_jwt_access=True,
             )
 
     # Check the case api_endpoint is not provided and GOOGLE_API_USE_MTLS_ENDPOINT has
@@ -306,6 +304,7 @@ def test_reachability_service_client_client_options(
             client_cert_source_for_mtls=None,
             quota_project_id="octopus",
             client_info=transports.base.DEFAULT_CLIENT_INFO,
+            always_use_jwt_access=True,
         )
 
 
@@ -382,6 +381,7 @@ def test_reachability_service_client_mtls_env_auto(
                 client_cert_source_for_mtls=expected_client_cert_source,
                 quota_project_id=None,
                 client_info=transports.base.DEFAULT_CLIENT_INFO,
+                always_use_jwt_access=True,
             )
 
     # Check the case ADC client cert is provided. Whether client cert is used depends on
@@ -415,6 +415,7 @@ def test_reachability_service_client_mtls_env_auto(
                         client_cert_source_for_mtls=expected_client_cert_source,
                         quota_project_id=None,
                         client_info=transports.base.DEFAULT_CLIENT_INFO,
+                        always_use_jwt_access=True,
                     )
 
     # Check the case client_cert_source and ADC client cert are not provided.
@@ -436,6 +437,7 @@ def test_reachability_service_client_mtls_env_auto(
                     client_cert_source_for_mtls=None,
                     quota_project_id=None,
                     client_info=transports.base.DEFAULT_CLIENT_INFO,
+                    always_use_jwt_access=True,
                 )
 
 
@@ -470,6 +472,7 @@ def test_reachability_service_client_client_options_scopes(
             client_cert_source_for_mtls=None,
             quota_project_id=None,
             client_info=transports.base.DEFAULT_CLIENT_INFO,
+            always_use_jwt_access=True,
         )
 
 
@@ -504,6 +507,7 @@ def test_reachability_service_client_client_options_credentials_file(
             client_cert_source_for_mtls=None,
             quota_project_id=None,
             client_info=transports.base.DEFAULT_CLIENT_INFO,
+            always_use_jwt_access=True,
         )
 
 
@@ -523,6 +527,7 @@ def test_reachability_service_client_client_options_from_dict():
             client_cert_source_for_mtls=None,
             quota_project_id=None,
             client_info=transports.base.DEFAULT_CLIENT_INFO,
+            always_use_jwt_access=True,
         )