diff --git a/litellm/completion_extras/litellm_responses_transformation/transformation.py b/litellm/completion_extras/litellm_responses_transformation/transformation.py
index aecb2552b53..619a42ff404 100644
--- a/litellm/completion_extras/litellm_responses_transformation/transformation.py
+++ b/litellm/completion_extras/litellm_responses_transformation/transformation.py
@@ -1074,6 +1074,7 @@ class LiteLLMResponsesTransformationHandler(CompletionTransformationBridge):
 class OpenAiResponsesToChatCompletionStreamIterator(BaseModelResponseIterator):
     def __init__(self, streaming_response, sync_stream: bool, json_mode: Optional[bool] = False):
         super().__init__(streaming_response, sync_stream, json_mode)
+        self.response_id: Optional[str] = None
 
     def _handle_string_chunk(
         self, str_line: Union[str, "BaseModel"]
@@ -1381,4 +1382,9 @@ class OpenAiResponsesToChatCompletionStreamIterator(BaseModelResponseIterator):
             ModelResponseStream: OpenAI-formatted streaming chunk
         """
         verbose_logger.debug(f"Chat provider: transform_streaming_response called with chunk: {chunk}")
-        return OpenAiResponsesToChatCompletionStreamIterator.translate_responses_chunk_to_openai_stream(chunk)
+        model_response = OpenAiResponsesToChatCompletionStreamIterator.translate_responses_chunk_to_openai_stream(chunk)
+        if self.response_id is None:
+            self.response_id = model_response.id
+        else:
+            model_response.id = self.response_id
+        return model_response
diff --git a/tests/test_litellm/completion_extras/litellm_responses_transformation/test_completion_extras_litellm_responses_transformation_transformation.py b/tests/test_litellm/completion_extras/litellm_responses_transformation/test_completion_extras_litellm_responses_transformation_transformation.py
index 6a1de0586dd..4a4b334702f 100644
--- a/tests/test_litellm/completion_extras/litellm_responses_transformation/test_completion_extras_litellm_responses_transformation_transformation.py
+++ b/tests/test_litellm/completion_extras/litellm_responses_transformation/test_completion_extras_litellm_responses_transformation_transformation.py
@@ -336,6 +336,30 @@ def test_chunk_parser_function_call_added_produces_tool_use():
     assert choice.finish_reason is None
 
 
+def test_chunk_parser_reuses_id_across_response_events():
+    from litellm.completion_extras.litellm_responses_transformation.transformation import (
+        OpenAiResponsesToChatCompletionStreamIterator,
+    )
+
+    iterator = OpenAiResponsesToChatCompletionStreamIterator(
+        streaming_response=None, sync_stream=True
+    )
+
+    events = [
+        {"type": "response.created"},
+        {"type": "response.output_text.delta", "delta": "hello"},
+        {
+            "type": "response.function_call_arguments.delta",
+            "output_index": 0,
+            "delta": '{"city":"Paris"}',
+        },
+    ]
+
+    ids = {iterator.chunk_parser(event).id for event in events}
+
+    assert len(ids) == 1
+
+
 def test_transform_response_with_reasoning_and_output():
     """Test transform_response handles ResponsesAPIResponse with reasoning items and output messages."""
     from unittest.mock import Mock