diff --git a/litellm/llms/chatgpt/responses/transformation.py b/litellm/llms/chatgpt/responses/transformation.py
index 9774b762396..b53ec1e52da 100644
--- a/litellm/llms/chatgpt/responses/transformation.py
+++ b/litellm/llms/chatgpt/responses/transformation.py
@@ -35,6 +35,17 @@ from ..common_utils import (
 if TYPE_CHECKING:
     from litellm.litellm_core_utils.litellm_logging import Logging as LiteLLMLoggingObj
 
+_STRUCTURED_OUTPUT_FORMAT_TYPES: Final = frozenset({"json_schema", "json_object"})
+
+
+def _has_structured_output_format(text: object) -> bool:
+    if not isinstance(text, dict):
+        return False
+    format_config: Final = text.get("format")
+    if not isinstance(format_config, dict):
+        return False
+    return format_config.get("type") in _STRUCTURED_OUTPUT_FORMAT_TYPES
+
 
 class ChatGPTResponsesAPIConfig(OpenAIResponsesAPIConfig):
     def __init__(self) -> None:
@@ -106,6 +117,7 @@ class ChatGPTResponsesAPIConfig(OpenAIResponsesAPIConfig):
             "reasoning",
             "previous_response_id",
             "truncation",
+            *(("text",) if _has_structured_output_format(request.get("text")) else ()),
         }
 
         return {k: v for k, v in request.items() if k in allowed_keys}
diff --git a/tests/unit/llms/chatgpt/responses/test_chatgpt_responses_transformation.py b/tests/unit/llms/chatgpt/responses/test_chatgpt_responses_transformation.py
index 0b04dd0ed78..06543396678 100644
--- a/tests/unit/llms/chatgpt/responses/test_chatgpt_responses_transformation.py
+++ b/tests/unit/llms/chatgpt/responses/test_chatgpt_responses_transformation.py
@@ -196,6 +196,55 @@ class TestChatGPTResponsesAPITransformation:
             "function": {"name": "hello"},
         }
 
+    @pytest.mark.parametrize(
+        "text_param",
+        [
+            {
+                "format": {
+                    "type": "json_schema",
+                    "name": "verdict",
+                    "schema": {
+                        "type": "object",
+                        "properties": {"block": {"type": "boolean"}},
+                        "required": ["block"],
+                    },
+                }
+            },
+            {"format": {"type": "json_object"}},
+        ],
+    )
+    def test_chatgpt_preserves_structured_output_text(self, text_param):
+        config = ChatGPTResponsesAPIConfig()
+        request = config.transform_responses_api_request(
+            model="chatgpt/gpt-5.3-codex",
+            input="hi",
+            response_api_optional_request_params={"text": text_param},
+            litellm_params=GenericLiteLLMParams(),
+            headers={},
+        )
+
+        assert request["text"] == text_param
+
+    @pytest.mark.parametrize(
+        "text_param",
+        [
+            {"format": {"type": "text"}},
+            {"verbosity": "low"},
+            "not-a-dict",
+        ],
+    )
+    def test_chatgpt_drops_non_structured_text_param(self, text_param):
+        config = ChatGPTResponsesAPIConfig()
+        request = config.transform_responses_api_request(
+            model="chatgpt/gpt-5.3-codex",
+            input="hi",
+            response_api_optional_request_params={"text": text_param},
+            litellm_params=GenericLiteLLMParams(),
+            headers={},
+        )
+
+        assert "text" not in request
+
     @pytest.mark.parametrize(
         ("model_name", "response_model"),
         [