diff --git a/litellm/llms/bedrock/chat/converse_transformation.py b/litellm/llms/bedrock/chat/converse_transformation.py
index a54251f3dfd..2818d46548a 100644
--- a/litellm/llms/bedrock/chat/converse_transformation.py
+++ b/litellm/llms/bedrock/chat/converse_transformation.py
@@ -126,6 +126,12 @@ class AmazonConverseConfig(BaseConfig):
     temperature: int | None
     topP: int | None
     topK: int | None
+    # Opaque-id fallback for adaptive-thinking capability resolution (an
+    # application inference profile ARN in `model` carries no version
+    # substring). Set by the caller (get_optional_params) before
+    # map_openai_params runs; not a constructor param, so map_openai_params's
+    # override stays signature-compatible with BaseConfig.
+    configured_base_model: str | None = None
 
     def __init__(
         self,
@@ -878,8 +884,15 @@ class AmazonConverseConfig(BaseConfig):
         optional_params: dict,
         model: str,
         drop_params: bool,
-        base_model: str | None = None,
     ) -> dict:
+        # Application inference profile ARNs carry no version substring, so the
+        # adaptive-thinking capability lookup below resolves nothing for them.
+        # `configured_base_model` is the opaque-id fallback set by the caller
+        # (get_optional_params, from litellm_params.base_model) — same role as
+        # Azure's base_model, threaded via an instance attribute rather than a
+        # map_openai_params parameter so the override stays compatible with
+        # BaseConfig's shared signature.
+        base_model: Final = self.configured_base_model
         is_thinking_enabled: Final = self.is_thinking_enabled(non_default_params)
 
         for param, value in non_default_params.items():
diff --git a/litellm/utils.py b/litellm/utils.py
index 8f4da474144..6ffe1d9c003 100644
--- a/litellm/utils.py
+++ b/litellm/utils.py
@@ -4418,12 +4418,16 @@ def get_optional_params(
         bedrock_route: Final = BedrockModelInfo.get_bedrock_route(model)
         bedrock_base_model: Final = BedrockModelInfo.get_base_model(model)
         if bedrock_route == "converse" or bedrock_route == "converse_like":
-            optional_params = litellm.AmazonConverseConfig().map_openai_params(
+            _converse_config: Final = litellm.AmazonConverseConfig()
+            # Set before the call, read via getattr inside map_openai_params —
+            # keeps the override signature-compatible with BaseConfig. See the
+            # comment on that method for why.
+            _converse_config.configured_base_model = base_model
+            optional_params = _converse_config.map_openai_params(
                 model=model,
                 non_default_params=non_default_params,
                 optional_params=optional_params,
                 drop_params=(drop_params if drop_params is not None and isinstance(drop_params, bool) else False),
-                base_model=base_model,
             )
         elif bedrock_route == "openai":
             optional_params = litellm.AmazonBedrockOpenAIConfig().map_openai_params(