diff --git a/litellm/proxy/auth/auth_checks.py b/litellm/proxy/auth/auth_checks.py
index 840f64cfede..3f9cd4cf867 100644
--- a/litellm/proxy/auth/auth_checks.py
+++ b/litellm/proxy/auth/auth_checks.py
@@ -915,7 +915,8 @@ async def get_team_member_default_budget(
     Fetches the team-level default per-member budget referenced by team.metadata["team_member_budget_id"].
 
     This budget is applied to team members whose TeamMembership row has no
-    linked budget. Results are cached for performance.
+    linked budget, or whose linked budget has max_budget=NULL. Results are
+    cached for performance.
 
     Args:
         budget_id: The budget_id pulled from team.metadata["team_member_budget_id"]
@@ -3293,6 +3294,7 @@ async def _check_team_member_budget(
         if (
             team_membership is not None
             and team_membership.litellm_budget_table is not None
+            and team_membership.litellm_budget_table.max_budget is not None
         ):
             team_member_budget = team_membership.litellm_budget_table.max_budget
         else:
diff --git a/tests/test_litellm/proxy/auth/test_auth_checks.py b/tests/test_litellm/proxy/auth/test_auth_checks.py
index 676a32c2027..841b45cef82 100644
--- a/tests/test_litellm/proxy/auth/test_auth_checks.py
+++ b/tests/test_litellm/proxy/auth/test_auth_checks.py
@@ -2336,3 +2336,134 @@ async def test_team_member_budget_check_per_member_override_wins_over_team_defau
             )
     assert exc_info.value.current_cost == 250.0
     assert exc_info.value.max_budget == 200.0
+
+
+@pytest.mark.asyncio
+async def test_team_member_budget_check_null_clone_falls_back_to_team_default():
+    """Per-member NULL max_budget falls through to the team default cap."""
+    from litellm.caching.dual_cache import DualCache
+    from litellm.proxy._types import LiteLLM_BudgetTable, LiteLLM_TeamMembership
+    from litellm.proxy.utils import ProxyLogging
+
+    team_object = LiteLLM_TeamTable(
+        team_id="test-team",
+        metadata={"team_member_budget_id": "budget-default"},
+    )
+    user_object = LiteLLM_UserTable(user_id="test-user")
+    valid_token = UserAPIKeyAuth(
+        token="test-token",
+        user_id="test-user",
+        team_id="test-team",
+    )
+
+    # Per-member row exists with NULL max_budget (the cloned-from-incomplete-default case).
+    team_membership = LiteLLM_TeamMembership(
+        user_id="test-user",
+        team_id="test-team",
+        spend=0.0,
+        budget_id="budget-clone",
+        litellm_budget_table=LiteLLM_BudgetTable(max_budget=None),
+    )
+
+    proxy_logging_obj = ProxyLogging(user_api_key_cache=None)
+
+    fake_default_row = MagicMock()
+    fake_default_row.max_budget = 65.0
+    fake_default_row.dict = MagicMock(
+        return_value={"budget_id": "budget-default", "max_budget": 65.0}
+    )
+
+    prisma_client = MagicMock()
+    prisma_client.db.litellm_budgettable.find_unique = AsyncMock(
+        return_value=fake_default_row
+    )
+
+    async def mock_get_current_spend(counter_key, fallback_spend):
+        if counter_key == "spend:team_member:test-user:test-team":
+            return 500.0
+        return fallback_spend
+
+    with (
+        patch("litellm.proxy.proxy_server.get_current_spend", mock_get_current_spend),
+        patch(
+            "litellm.proxy.auth.auth_checks.get_team_membership",
+            new_callable=AsyncMock,
+            return_value=team_membership,
+        ),
+    ):
+        with pytest.raises(litellm.BudgetExceededError) as exc_info:
+            await _check_team_member_budget(
+                team_object=team_object,
+                user_object=user_object,
+                valid_token=valid_token,
+                prisma_client=prisma_client,
+                user_api_key_cache=DualCache(),
+                proxy_logging_obj=proxy_logging_obj,
+            )
+
+    assert exc_info.value.current_cost == 500.0
+    assert exc_info.value.max_budget == 65.0
+    prisma_client.db.litellm_budgettable.find_unique.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_team_member_budget_check_null_clone_with_null_default_skips_enforcement():
+    """When per-member and team default are both NULL, enforcement still skips."""
+    from litellm.caching.dual_cache import DualCache
+    from litellm.proxy._types import LiteLLM_BudgetTable, LiteLLM_TeamMembership
+    from litellm.proxy.utils import ProxyLogging
+
+    team_object = LiteLLM_TeamTable(
+        team_id="test-team",
+        metadata={"team_member_budget_id": "budget-default"},
+    )
+    user_object = LiteLLM_UserTable(user_id="test-user")
+    valid_token = UserAPIKeyAuth(
+        token="test-token",
+        user_id="test-user",
+        team_id="test-team",
+    )
+
+    team_membership = LiteLLM_TeamMembership(
+        user_id="test-user",
+        team_id="test-team",
+        spend=0.0,
+        budget_id="budget-clone",
+        litellm_budget_table=LiteLLM_BudgetTable(max_budget=None),
+    )
+
+    proxy_logging_obj = ProxyLogging(user_api_key_cache=None)
+
+    fake_default_row = MagicMock()
+    fake_default_row.max_budget = None
+    fake_default_row.dict = MagicMock(
+        return_value={"budget_id": "budget-default", "max_budget": None}
+    )
+
+    prisma_client = MagicMock()
+    prisma_client.db.litellm_budgettable.find_unique = AsyncMock(
+        return_value=fake_default_row
+    )
+
+    async def mock_get_current_spend(counter_key, fallback_spend):
+        if counter_key == "spend:team_member:test-user:test-team":
+            return 1000.0
+        return fallback_spend
+
+    with (
+        patch("litellm.proxy.proxy_server.get_current_spend", mock_get_current_spend),
+        patch(
+            "litellm.proxy.auth.auth_checks.get_team_membership",
+            new_callable=AsyncMock,
+            return_value=team_membership,
+        ),
+    ):
+        # No raise: both rows are NULL, so enforcement is correctly skipped.
+        await _check_team_member_budget(
+            team_object=team_object,
+            user_object=user_object,
+            valid_token=valid_token,
+            prisma_client=prisma_client,
+            user_api_key_cache=DualCache(),
+            proxy_logging_obj=proxy_logging_obj,
+        )