diff --git a/litellm/litellm_core_utils/exception_mapping_utils.py b/litellm/litellm_core_utils/exception_mapping_utils.py
index d23466938f2..ee179b582cf 100644
--- a/litellm/litellm_core_utils/exception_mapping_utils.py
+++ b/litellm/litellm_core_utils/exception_mapping_utils.py
@@ -2315,7 +2315,7 @@ def exception_type(
                     exception_provider=exception_provider,
                     extra_information=extra_information,
                 )
-            elif custom_llm_provider == "bedrock":
+            elif custom_llm_provider in ("bedrock", "bedrock_mantle"):
                 _map_bedrock_exception(
                     model=model,
                     original_exception=mappable_exception,
diff --git a/tests/test_litellm/litellm_core_utils/test_exception_mapping_utils.py b/tests/test_litellm/litellm_core_utils/test_exception_mapping_utils.py
index d5676aaf288..904675d4adc 100644
--- a/tests/test_litellm/litellm_core_utils/test_exception_mapping_utils.py
+++ b/tests/test_litellm/litellm_core_utils/test_exception_mapping_utils.py
@@ -762,3 +762,26 @@ def test_azure_404_with_invalid_request_error_type_maps_to_not_found():
 
     assert excinfo.value.status_code == 404
     assert "Response with id 'resp_abc' not found." in excinfo.value.message
+
+
+def test_bedrock_mantle_400_maps_to_bad_request():
+    from litellm.llms.base_llm.chat.transformation import BaseLLMException
+
+    original_exception = BaseLLMException(
+        status_code=400,
+        message=(
+            '{"error": {"code": "validation_error", "message": '
+            "\"invalid request body: Invalid 'input': value did not match any expected variant\", "
+            '"type": "invalid_request_error"}}'
+        ),
+    )
+
+    with pytest.raises(litellm.BadRequestError) as excinfo:
+        exception_type(
+            model="gpt-5.6-terra",
+            original_exception=original_exception,
+            custom_llm_provider="bedrock_mantle",
+        )
+
+    assert excinfo.value.status_code == 400
+    assert "Invalid 'input'" in excinfo.value.message