diff --git a/litellm/llms/bedrock/chat/converse_transformation.py b/litellm/llms/bedrock/chat/converse_transformation.py
index 497020c2836..2315243b10f 100644
--- a/litellm/llms/bedrock/chat/converse_transformation.py
+++ b/litellm/llms/bedrock/chat/converse_transformation.py
@@ -508,7 +508,9 @@ class AmazonConverseConfig(BaseConfig):
             }
         }
 
-    def _handle_reasoning_effort_parameter(self, model: str, reasoning_effort: str, optional_params: dict) -> None:
+    def _handle_reasoning_effort_parameter(
+        self, model: str, reasoning_effort: str, optional_params: dict, max_tokens: int | None = None
+    ) -> None:
         """
         Handle the reasoning_effort parameter based on the model type.
 
@@ -527,12 +529,14 @@ class AmazonConverseConfig(BaseConfig):
             reasoning_config: Final = self._transform_reasoning_effort_to_reasoning_config(reasoning_effort)
             optional_params.update(reasoning_config)
         else:
-            mapped_thinking: Final = AnthropicConfig._map_reasoning_effort(
+            mapped_thinking = AnthropicConfig._map_reasoning_effort(
                 reasoning_effort=reasoning_effort,
                 model=model,
                 custom_llm_provider="bedrock",
                 llm_provider="bedrock_converse",
             )
+            if mapped_thinking is not None:
+                mapped_thinking = AnthropicConfig.cap_thinking_budget_to_max_tokens(mapped_thinking, max_tokens)
             if mapped_thinking is None:
                 optional_params.pop("thinking", None)
                 optional_params.pop("output_config", None)
@@ -1113,7 +1117,10 @@ class AmazonConverseConfig(BaseConfig):
                 )
             elif param == "reasoning_effort" and isinstance(value, str):
                 self._handle_reasoning_effort_parameter(
-                    model=model, reasoning_effort=value, optional_params=optional_params
+                    model=model,
+                    reasoning_effort=value,
+                    optional_params=optional_params,
+                    max_tokens=non_default_params.get("max_completion_tokens") or non_default_params.get("max_tokens"),
                 )
             elif param == "output_config" and isinstance(value, dict):
                 mapped_output_config = dict(value)
diff --git a/tests/test_litellm/llms/bedrock/chat/test_converse_transformation.py b/tests/test_litellm/llms/bedrock/chat/test_converse_transformation.py
index ad77f9d4d1b..6dbf09217d9 100644
--- a/tests/test_litellm/llms/bedrock/chat/test_converse_transformation.py
+++ b/tests/test_litellm/llms/bedrock/chat/test_converse_transformation.py
@@ -575,6 +575,36 @@ def test_reasoning_effort_none_omits_thinking_for_anthropic_converse(model):
     assert "thinking" not in optional_params
 
 
+@pytest.mark.parametrize(
+    "max_tokens,expect_thinking,expect_budget_below_max_tokens",
+    [
+        (1024, False, None),
+        (2048, True, True),
+        (4096, True, False),
+    ],
+)
+def test_reasoning_effort_thinking_budget_clamped_to_max_tokens_converse(
+    max_tokens: int, expect_thinking: bool, expect_budget_below_max_tokens: bool | None
+) -> None:
+    """Regression #39627."""
+    config = AmazonConverseConfig()
+
+    optional_params = config.map_openai_params(
+        non_default_params={"max_tokens": max_tokens, "reasoning_effort": "medium"},
+        optional_params={},
+        model="us.anthropic.claude-haiku-4-5-20251001-v1:0",
+        drop_params=False,
+    )
+
+    if not expect_thinking:
+        assert optional_params.get("thinking") is None
+        return
+
+    thinking = optional_params["thinking"]
+    budget = thinking["budget_tokens"]
+    assert budget < max_tokens if expect_budget_below_max_tokens else budget == 2048
+
+
 @pytest.mark.parametrize(
     "model,effort,expected_effort",
     [