diff --git a/src/ell/providers/openai.py b/src/ell/providers/openai.py
index 8fe7f4d1b..a9d70d874 100644
--- a/src/ell/providers/openai.py
+++ b/src/ell/providers/openai.py
@@ -83,7 +83,8 @@ def translate_to_provider(self, ell_call : EllCallParams) -> Dict[str, Any]:
                         role=message.role,
                         content=[_content_block_to_openai_format(c) for c in message.content] 
                              if message.role != "system" 
-                             else message.text_only
+                             else message.text_only,
+                        tool_call_id=message.tool_call_id
                     )))
                      
             final_call_params["messages"] = openai_messages
@@ -159,7 +160,7 @@ def translate_from_provider(
                                     )
                                 )
                                 if logger: logger(repr(tool_call))
-                    messages.append(Message(role=role, content=content_blocks))
+                    messages.append(Message(role=role, content=content_blocks, tool_call_id=message.tool_call_id))
             return messages, metadata
 
 
@@ -181,4 +182,4 @@ def _content_block_to_openai_format(content_block: ContentBlock) -> Dict[str, An
     elif ((text := content_block.text) is not None): return dict(type="text", text=text)
     elif (parsed := content_block.parsed): return dict(type="text", text=parsed.model_dump_json())    
     else:
-        raise ValueError(f"Unsupported content block type for openai: {content_block}")
\ No newline at end of file
+        raise ValueError(f"Unsupported content block type for openai: {content_block}")
diff --git a/src/ell/types/message.py b/src/ell/types/message.py
index 93b8fc5c0..92e6bc2a0 100644
--- a/src/ell/types/message.py
+++ b/src/ell/types/message.py
@@ -312,12 +312,11 @@ def to_content_blocks(
 class Message(BaseModel):
     role: str
     content: List[ContentBlock]
-    
+    tool_call_id: Optional[_lstr_generic] = Field(default=None)
 
-    def __init__(self, role: str, content: Union[AnyContent, List[AnyContent], None] = None, **content_block_kwargs):
+    def __init__(self, role: str, content: Union[AnyContent, List[AnyContent], None] = None, tool_call_id: Optional[_lstr_generic] = None, **content_block_kwargs):
         content_blocks = to_content_blocks(content, **content_block_kwargs)
-        
-        super().__init__(role=role, content=content_blocks)
+        super().__init__(role=role, content=content_blocks, tool_call_id=tool_call_id)
 
     # XXX: This choice of naming is unfortunate, but it is what it is.
     @property
@@ -452,6 +451,8 @@ def model_validate(cls, obj: Any) -> 'Message':
                     else:
                         content_blocks.append(ContentBlock.coerce(block))
                 obj['content'] = content_blocks
+            if 'tool_call_id' in obj:
+                obj['tool_call_id'] = _lstr(obj['tool_call_id'])
         return super().model_validate(obj)
 
     @classmethod