diff --git a/litellm/litellm_core_utils/llm_cost_calc/tool_call_cost_tracking.py b/litellm/litellm_core_utils/llm_cost_calc/tool_call_cost_tracking.py
index 4454fca3b00..8da66d4600d 100644
--- a/litellm/litellm_core_utils/llm_cost_calc/tool_call_cost_tracking.py
+++ b/litellm/litellm_core_utils/llm_cost_calc/tool_call_cost_tracking.py
@@ -322,9 +322,8 @@ class StandardBuiltInToolCostTracking:
             )
             if has_url_citations:
                 return True
-            # Fallback: Check usage object for providers that use usage instead of annotations
-            # (e.g., Vertex AI Gemini uses usage.prompt_tokens_details.web_search_requests)
             if usage is not None:
+                # Vertex AI Gemini uses usage.prompt_tokens_details.web_search_requests
                 if (
                     hasattr(usage, "prompt_tokens_details")
                     and usage.prompt_tokens_details is not None
@@ -335,6 +334,15 @@ class StandardBuiltInToolCostTracking:
                     and usage.prompt_tokens_details.web_search_requests is not None
                 ):
                     return True
+                # Anthropic Claude (direct API and Vertex AI) uses server_tool_use.web_search_requests.
+                # Without this check, Claude ModelResponse always falls through to return False
+                # and _handle_web_search_cost() is never called.
+                if (
+                    hasattr(usage, "server_tool_use")
+                    and usage.server_tool_use is not None
+                    and usage.server_tool_use.web_search_requests is not None
+                ):
+                    return True
             return False
         elif isinstance(response_object, ResponsesAPIResponse):
             # response api explicitly includes web_search_call in the output
diff --git a/litellm/llms/__init__.py b/litellm/llms/__init__.py
index c73f0b22b4b..710342bbc78 100644
--- a/litellm/llms/__init__.py
+++ b/litellm/llms/__init__.py
@@ -34,6 +34,18 @@ def get_cost_for_web_search_request(
 
         return get_cost_for_anthropic_web_search(model_info=model_info, usage=usage)
     elif custom_llm_provider.startswith("vertex_ai"):
+        # Anthropic Claude models on Vertex AI populate server_tool_use.web_search_requests
+        # (same as the direct Anthropic API), not prompt_tokens_details.web_search_requests
+        # (which is the Gemini field). Route claude-* models to the Anthropic calculator.
+        model_key: str = model_info.get("key", "") if model_info else ""
+        if "claude" in model_key.lower():
+            from .anthropic.cost_calculation import get_cost_for_anthropic_web_search
+
+            verbose_logger.debug(
+                "vertex_ai/claude model detected — routing web search cost to Anthropic calculator"
+            )
+            return get_cost_for_anthropic_web_search(model_info=model_info, usage=usage)
+
         from .vertex_ai.gemini.cost_calculator import (
             cost_per_web_search_request as cost_per_web_search_request_vertex_ai,
         )