diff --git a/litellm/proxy/auth/auth_checks.py b/litellm/proxy/auth/auth_checks.py
index 8fbeaf18460..f43a4a92a57 100644
--- a/litellm/proxy/auth/auth_checks.py
+++ b/litellm/proxy/auth/auth_checks.py
@@ -138,6 +138,7 @@ from litellm.repositories.table_repositories import (
 from litellm.repositories.team_repository import TeamRepository
 from litellm.repositories.user_repository import UserRepository
 from litellm.router import Router
+from litellm.router_utils.common_utils import resolve_model_group_alias
 from litellm.types.proxy.auth.auth_checks import UserNotFoundError
 from litellm.types.proxy.model_access_group_budget import ModelAccessGroupBudget
 from litellm.utils import get_utc_datetime
@@ -479,7 +480,8 @@ def _is_model_cost_zero(model: str | list[str] | None, llm_router: Router | None
                 continue
         try:
             # Use router's get_model_group_info method directly for better reliability
-            model_group_info = llm_router.get_model_group_info(model_group=model_name)
+            target_group = resolve_model_group_alias(llm_router.model_group_alias, model_name) or model_name
+            model_group_info = llm_router.get_model_group_info(model_group=target_group)
 
             if model_group_info is None:
                 # Model not found or no pricing info available
diff --git a/tests/test_litellm/proxy/auth/test_unmapped_model_budget_enforcement.py b/tests/test_litellm/proxy/auth/test_unmapped_model_budget_enforcement.py
index 7665008a6a6..ebb97c6a29b 100644
--- a/tests/test_litellm/proxy/auth/test_unmapped_model_budget_enforcement.py
+++ b/tests/test_litellm/proxy/auth/test_unmapped_model_budget_enforcement.py
@@ -285,9 +285,12 @@ class TestUnmappedModelBudgetEnforcement:
             "An aliased PTU group must not be read as free"
         )
 
-    def test_hidden_model_group_alias_enforces_budget(self):
-        """A hidden alias keeps budget enforced: get_model_group_info() returns None for it,
-        so the cost is unknown before the configuration gate is reached."""
+    def test_hidden_model_group_alias_to_free_model_bypasses_budget(self):
+        """A hidden alias to an explicitly free group bypasses budget, like the group itself.
+
+        ``get_model_group_info`` returns None for hidden aliases, so the alias must be
+        resolved to its target group before the cost lookup.
+        """
         router = Router(
             model_list=[
                 {
@@ -304,7 +307,22 @@ class TestUnmappedModelBudgetEnforcement:
             model_group_alias={"hidden-alias": {"model": "free-model", "hidden": True}},
         )
 
-        assert _is_model_cost_zero(model="hidden-alias", llm_router=router) is False
+        assert _is_model_cost_zero(model="hidden-alias", llm_router=router) is True
+
+    def test_hidden_model_group_alias_to_paid_model_enforces_budget(self):
+        """A hidden alias to a priced group keeps budget enforced."""
+        router = Router(
+            model_list=[
+                {
+                    "model_name": "paid-model",
+                    "litellm_params": {"model": "gpt-3.5-turbo", "api_key": "sk-fake"},
+                    "model_info": {"id": "paid-model-id"},
+                },
+            ],
+            model_group_alias={"hidden-paid-alias": {"model": "paid-model", "hidden": True}},
+        )
+
+        assert _is_model_cost_zero(model="hidden-paid-alias", llm_router=router) is False
 
     def test_dangling_model_group_alias_enforces_budget(self):
         """An alias pointing at a group that does not exist keeps budget enforced."""