diff --git a/litellm/proxy/pass_through_endpoints/llm_provider_handlers/vertex_passthrough_logging_handler.py b/litellm/proxy/pass_through_endpoints/llm_provider_handlers/vertex_passthrough_logging_handler.py
index b667a7916fb..960e4d5882b 100644
--- a/litellm/proxy/pass_through_endpoints/llm_provider_handlers/vertex_passthrough_logging_handler.py
+++ b/litellm/proxy/pass_through_endpoints/llm_provider_handlers/vertex_passthrough_logging_handler.py
@@ -35,6 +35,8 @@ from litellm.types.utils import (
 )
 
 vertex_search_api_config: Final = VertexSearchAPIVectorStoreConfig()
+GEMINI_API_HOST_SUFFIX: Final = "generativelanguage.googleapis.com"
+VERTEX_API_HOST_SUFFIX: Final = "aiplatform.googleapis.com"
 if TYPE_CHECKING:
     from litellm.types.utils import LiteLLMBatch
 
@@ -560,10 +562,15 @@ class VertexPassthroughLoggingHandler:
             return "openapi"
         return None
 
+    @staticmethod
+    def is_google_ai_host(url: str) -> bool:
+        hostname: Final = urlparse(url).hostname
+        return hostname is not None and hostname.endswith((GEMINI_API_HOST_SUFFIX, VERTEX_API_HOST_SUFFIX))
+
     @staticmethod
     def custom_llm_provider_from_url(url: str) -> str:
         parsed_url: Final = urlparse(url)
-        if parsed_url.hostname and parsed_url.hostname.endswith("generativelanguage.googleapis.com"):
+        if parsed_url.hostname and parsed_url.hostname.endswith(GEMINI_API_HOST_SUFFIX):
             return litellm.LlmProviders.GEMINI.value
         return litellm.LlmProviders.VERTEX_AI.value
 
diff --git a/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py b/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py
index e59907bfa4c..eb81a02871e 100644
--- a/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py
+++ b/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py
@@ -735,7 +735,9 @@ def _carry_guardrail_logging_info(request_data: dict, guardrail_data: dict | Non
 def _passthrough_google_provider(url_route: str, custom_llm_provider: str | None) -> str | None:
     if pass_through_endpoint_logging.is_gemini_route(url_route, custom_llm_provider):
         return "gemini"
-    if pass_through_endpoint_logging.is_vertex_route(url_route):
+    if pass_through_endpoint_logging.is_vertex_route(url_route) or VertexPassthroughLoggingHandler.is_google_ai_host(
+        url_route
+    ):
         return VertexPassthroughLoggingHandler.custom_llm_provider_from_url(url_route)
     return None
 
diff --git a/tests/test_litellm/proxy/pass_through_endpoints/test_pass_through_endpoints.py b/tests/test_litellm/proxy/pass_through_endpoints/test_pass_through_endpoints.py
index 79c2e7fb3e9..f79b755f84e 100644
--- a/tests/test_litellm/proxy/pass_through_endpoints/test_pass_through_endpoints.py
+++ b/tests/test_litellm/proxy/pass_through_endpoints/test_pass_through_endpoints.py
@@ -5897,6 +5897,8 @@ def _upstream_400_as_event_stream(target: str) -> httpx.Response:
         (_GEMINI_FLASH_TARGET, "gemini", True, "gemini"),
         (_VERTEX_FLASH_TARGET, None, False, "vertex_ai"),
         (_VERTEX_FLASH_TARGET, None, True, "vertex_ai"),
+        (_GEMINI_FLASH_TARGET.replace(":generateContent", ":countTokens"), "gemini", False, "gemini"),
+        (_VERTEX_FLASH_TARGET.replace(":generateContent", ":countTokens"), None, False, "vertex_ai"),
     ],
 )
 async def test_passthrough_upstream_error_logs_model_from_url(
@@ -5986,6 +5988,36 @@ async def test_passthrough_mid_stream_drop_logs_model_from_url(
             "",
             "vertex_ai",
         ),
+        (
+            {"contents": []},
+            _GEMINI_FLASH_TARGET.replace(":generateContent", ":countTokens"),
+            "gemini",
+            "gemini-3.8-flash",
+            "gemini",
+        ),
+        (
+            {"contents": []},
+            _VERTEX_FLASH_TARGET.replace(":generateContent", ":countTokens"),
+            None,
+            "gemini-3.8-flash",
+            "vertex_ai",
+        ),
+        (
+            {"contents": []},
+            "https://aiplatform.googleapis.com/v1/projects/p/locations/global"
+            "/publishers/google/models/gemini-3.8-flash:countTokens",
+            None,
+            "gemini-3.8-flash",
+            "vertex_ai",
+        ),
+        (
+            {},
+            "https://us-central1-aiplatform.googleapis.com/v1/projects/p/locations/us-central1/cachedContents",
+            None,
+            "",
+            "vertex_ai",
+        ),
+        ({"contents": []}, "https://api.example.com/v1/models/gpt-x:countTokens", None, "", None),
         ({"contents": []}, "https://api.example.com/v1/models/gpt-x:thing", None, "", None),
         (None, None, None, "", None),
     ],