diff --git a/litellm/proxy/management_endpoints/scim/scim_v2.py b/litellm/proxy/management_endpoints/scim/scim_v2.py
index 069f86c852c..a8e9dc7c504 100644
--- a/litellm/proxy/management_endpoints/scim/scim_v2.py
+++ b/litellm/proxy/management_endpoints/scim/scim_v2.py
@@ -1762,6 +1762,10 @@ async def update_user(
         client_set_active: Final = "active" in user.model_fields_set
         scim_active_for_metadata: Final = user_data["active"] if client_set_active else prev_active
 
+        client_set_groups: Final = "groups" in user.model_fields_set
+        existing_teams: Final = list(existing_user.teams or [])
+        new_teams: Final = user_data["teams"] if client_set_groups else existing_teams
+
         metadata: Final = _build_scim_metadata(
             user_data["given_name"],
             user_data["family_name"],
@@ -1773,20 +1777,20 @@ async def update_user(
 
         await _handle_team_membership_changes(
             user_id=user_id,
-            existing_teams=existing_user.teams or [],
-            new_teams=user_data["teams"],
+            existing_teams=existing_teams,
+            new_teams=new_teams,
         )
 
         update_data: Final = {
             "user_email": user_data["user_email"],
             "user_alias": user_data["user_alias"],
             "sso_user_id": user_data["sso_user_id"],
-            "teams": user_data["teams"],
+            "teams": new_teams,
             "metadata": safe_dumps(metadata),
         }
 
         admin_group: Final = await _get_scim_admin_group()
-        if admin_group is not None:
+        if admin_group is not None and client_set_groups:
             update_data["user_role"] = _resolve_scim_user_role(
                 user.groups or [], admin_group, _default_scim_user_role()
             )
diff --git a/tests/test_litellm/proxy/management_endpoints/scim/test_scim_v2_endpoints.py b/tests/test_litellm/proxy/management_endpoints/scim/test_scim_v2_endpoints.py
index 1697b77b99a..4e3af2dd3e5 100644
--- a/tests/test_litellm/proxy/management_endpoints/scim/test_scim_v2_endpoints.py
+++ b/tests/test_litellm/proxy/management_endpoints/scim/test_scim_v2_endpoints.py
@@ -1176,6 +1176,92 @@ async def test_update_user_success(mocker):
     assert call_args[1]["data"]["teams"] == ["new-team"]
 
 
+@pytest.mark.asyncio
+async def test_update_user_without_groups_preserves_memberships(mocker):
+    """PUT /Users with `groups` omitted must leave team memberships and role untouched.
+
+    Regression: IdPs that sync membership only through /Groups omit `groups` on a
+    profile update, and the empty default was applied as "remove from every team".
+    """
+    existing_user = mocker.MagicMock()
+    existing_user.teams = ["team1", "team2"]
+    existing_user.metadata = {}
+
+    scim_user = SCIMUser(
+        schemas=["urn:ietf:params:scim:schemas:core:2.0:User"],
+        userName="test-user",
+        name=SCIMUserName(familyName="User", givenName="Renamed"),
+        emails=[SCIMUserEmail(value="renamed@example.com")],
+    )
+
+    mock_prisma_client = mocker.MagicMock()
+    mock_prisma_client.db.litellm_usertable.update = AsyncMock(return_value={"user_id": "test-user"})
+    mocker.patch(
+        "litellm.proxy.management_endpoints.scim.scim_v2._get_prisma_client_or_raise_exception",
+        AsyncMock(return_value=mock_prisma_client),
+    )
+    mocker.patch(
+        "litellm.proxy.management_endpoints.scim.scim_v2._check_user_exists",
+        AsyncMock(return_value=existing_user),
+    )
+    mocker.patch(
+        "litellm.proxy.management_endpoints.scim.scim_v2._get_scim_admin_group",
+        AsyncMock(return_value="admin-group"),
+    )
+    patch_membership = mocker.patch(
+        "litellm.proxy.management_endpoints.scim.scim_v2.patch_team_membership", AsyncMock()
+    )
+    mocker.patch(
+        "litellm.proxy.management_endpoints.scim.scim_v2.ScimTransformations.transform_litellm_user_to_scim_user",
+        AsyncMock(return_value=scim_user),
+    )
+
+    await update_user(user_id="test-user", user=scim_user)
+
+    patch_membership.assert_not_awaited()
+    update_data = mock_prisma_client.db.litellm_usertable.update.call_args[1]["data"]
+    assert update_data["teams"] == ["team1", "team2"]
+    assert update_data["user_email"] == "renamed@example.com"
+    assert "user_role" not in update_data
+
+
+@pytest.mark.asyncio
+async def test_update_user_with_explicit_empty_groups_removes_memberships(mocker):
+    """PUT /Users with `groups: []` sent explicitly still clears every team."""
+    existing_user = mocker.MagicMock()
+    existing_user.teams = ["team1"]
+
+    scim_user = SCIMUser(
+        schemas=["urn:ietf:params:scim:schemas:core:2.0:User"],
+        userName="test-user",
+        emails=[SCIMUserEmail(value="user@example.com")],
+        groups=[],
+    )
+
+    mock_prisma_client = mocker.MagicMock()
+    mock_prisma_client.db.litellm_usertable.update = AsyncMock(return_value={"user_id": "test-user"})
+    mocker.patch(
+        "litellm.proxy.management_endpoints.scim.scim_v2._get_prisma_client_or_raise_exception",
+        AsyncMock(return_value=mock_prisma_client),
+    )
+    mocker.patch(
+        "litellm.proxy.management_endpoints.scim.scim_v2._check_user_exists",
+        AsyncMock(return_value=existing_user),
+    )
+    patch_membership = mocker.patch(
+        "litellm.proxy.management_endpoints.scim.scim_v2.patch_team_membership", AsyncMock()
+    )
+    mocker.patch(
+        "litellm.proxy.management_endpoints.scim.scim_v2.ScimTransformations.transform_litellm_user_to_scim_user",
+        AsyncMock(return_value=scim_user),
+    )
+
+    await update_user(user_id="test-user", user=scim_user)
+
+    assert patch_membership.call_args[1]["teams_ids_to_remove_user_from"] == ["team1"]
+    assert mock_prisma_client.db.litellm_usertable.update.call_args[1]["data"]["teams"] == []
+
+
 @pytest.mark.asyncio
 async def test_update_user_not_found(mocker):
     """Should raise 404 when user doesn't exist"""