diff --git a/.chronus/changes/python-arm-service-group-tests-2026-7-27-8-59-27.md b/.chronus/changes/python-arm-service-group-tests-2026-7-27-8-59-27.md
new file mode 100644
index 00000000000..330b02ebc10
--- /dev/null
+++ b/.chronus/changes/python-arm-service-group-tests-2026-7-27-8-59-27.md
@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@typespec/http-client-python"
+---
+
+Add test coverage for Azure ARM service group extension resources and ARM resource identifier group scope
diff --git a/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_arm_servicegroup_async.py b/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_arm_servicegroup_async.py
new file mode 100644
index 00000000000..f10230c1e7e
--- /dev/null
+++ b/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_arm_servicegroup_async.py
@@ -0,0 +1,82 @@
+# -------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+import pytest
+import pytest_asyncio
+from azure.resourcemanager.servicegroupextension.aio import ServiceGroupExtensionClient
+from azure.resourcemanager.servicegroupextension import models
+
+SERVICE_GROUP_ID = "test-sg"
+RESOURCE_NAME = "resource"
+
+
+@pytest_asyncio.fixture
+async def client(credential, authentication_policy):
+    async with ServiceGroupExtensionClient(
+        credential, "http://localhost:3000", authentication_policy=authentication_policy
+    ) as client:
+        yield client
+
+
+@pytest.mark.asyncio
+async def test_service_group_extension_resources_get(client):
+    result = await client.service_group_extension_resources.get(
+        service_group_id=SERVICE_GROUP_ID, service_group_extension_resource_name=RESOURCE_NAME
+    )
+    assert result.name == RESOURCE_NAME
+    assert result.properties.description == "valid"
+    assert result.properties.provisioning_state == "Succeeded"
+
+
+@pytest.mark.asyncio
+async def test_service_group_extension_resources_create_or_update(client):
+    result = await (
+        await client.service_group_extension_resources.begin_create_or_update(
+            service_group_id=SERVICE_GROUP_ID,
+            service_group_extension_resource_name=RESOURCE_NAME,
+            resource=models.ServiceGroupExtensionResource(
+                properties=models.ServiceGroupExtensionResourceProperties(description="valid")
+            ),
+            polling_interval=0,
+        )
+    ).result()
+    assert result.name == RESOURCE_NAME
+    assert result.properties.description == "valid"
+    assert result.properties.provisioning_state == "Succeeded"
+
+
+@pytest.mark.asyncio
+async def test_service_group_extension_resources_update(client):
+    result = await client.service_group_extension_resources.update(
+        service_group_id=SERVICE_GROUP_ID,
+        service_group_extension_resource_name=RESOURCE_NAME,
+        properties=models.ServiceGroupExtensionResource(
+            properties=models.ServiceGroupExtensionResourceProperties(description="valid2")
+        ),
+    )
+    assert result.name == RESOURCE_NAME
+    assert result.properties.description == "valid2"
+    assert result.properties.provisioning_state == "Succeeded"
+
+
+@pytest.mark.asyncio
+async def test_service_group_extension_resources_delete(client):
+    await client.service_group_extension_resources.delete(
+        service_group_id=SERVICE_GROUP_ID, service_group_extension_resource_name=RESOURCE_NAME
+    )
+
+
+@pytest.mark.asyncio
+async def test_service_group_extension_resources_list_by_service_group(client):
+    result = [
+        item
+        async for item in client.service_group_extension_resources.list_by_service_group(
+            service_group_id=SERVICE_GROUP_ID
+        )
+    ]
+    assert len(result) == 1
+    assert result[0].name == RESOURCE_NAME
+    assert result[0].properties.description == "valid"
+    assert result[0].properties.provisioning_state == "Succeeded"
diff --git a/packages/http-client-python/tests/mock_api/azure/test_azure_arm_servicegroup.py b/packages/http-client-python/tests/mock_api/azure/test_azure_arm_servicegroup.py
new file mode 100644
index 00000000000..d2c8b8c29db
--- /dev/null
+++ b/packages/http-client-python/tests/mock_api/azure/test_azure_arm_servicegroup.py
@@ -0,0 +1,69 @@
+# -------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+import pytest
+from azure.resourcemanager.servicegroupextension import ServiceGroupExtensionClient
+from azure.resourcemanager.servicegroupextension import models
+
+SERVICE_GROUP_ID = "test-sg"
+RESOURCE_NAME = "resource"
+
+
+@pytest.fixture
+def client(credential, authentication_policy):
+    with ServiceGroupExtensionClient(
+        credential, "http://localhost:3000", authentication_policy=authentication_policy
+    ) as client:
+        yield client
+
+
+def test_service_group_extension_resources_get(client):
+    result = client.service_group_extension_resources.get(
+        service_group_id=SERVICE_GROUP_ID, service_group_extension_resource_name=RESOURCE_NAME
+    )
+    assert result.name == RESOURCE_NAME
+    assert result.properties.description == "valid"
+    assert result.properties.provisioning_state == "Succeeded"
+
+
+def test_service_group_extension_resources_create_or_update(client):
+    result = client.service_group_extension_resources.begin_create_or_update(
+        service_group_id=SERVICE_GROUP_ID,
+        service_group_extension_resource_name=RESOURCE_NAME,
+        resource=models.ServiceGroupExtensionResource(
+            properties=models.ServiceGroupExtensionResourceProperties(description="valid")
+        ),
+        polling_interval=0,
+    ).result()
+    assert result.name == RESOURCE_NAME
+    assert result.properties.description == "valid"
+    assert result.properties.provisioning_state == "Succeeded"
+
+
+def test_service_group_extension_resources_update(client):
+    result = client.service_group_extension_resources.update(
+        service_group_id=SERVICE_GROUP_ID,
+        service_group_extension_resource_name=RESOURCE_NAME,
+        properties=models.ServiceGroupExtensionResource(
+            properties=models.ServiceGroupExtensionResourceProperties(description="valid2")
+        ),
+    )
+    assert result.name == RESOURCE_NAME
+    assert result.properties.description == "valid2"
+    assert result.properties.provisioning_state == "Succeeded"
+
+
+def test_service_group_extension_resources_delete(client):
+    client.service_group_extension_resources.delete(
+        service_group_id=SERVICE_GROUP_ID, service_group_extension_resource_name=RESOURCE_NAME
+    )
+
+
+def test_service_group_extension_resources_list_by_service_group(client):
+    result = list(client.service_group_extension_resources.list_by_service_group(service_group_id=SERVICE_GROUP_ID))
+    assert len(result) == 1
+    assert result[0].name == RESOURCE_NAME
+    assert result[0].properties.description == "valid"
+    assert result[0].properties.provisioning_state == "Succeeded"