diff --git a/src/anthropic/_streaming.py b/src/anthropic/_streaming.py
index fc6943ee..e55f447c 100644
--- a/src/anthropic/_streaming.py
+++ b/src/anthropic/_streaming.py
@@ -17,6 +17,20 @@
     from ._client import Anthropic, AsyncAnthropic
     from ._models import FinalRequestOptions
 
+# Mapping from SSE error type to HTTP status code.
+# When a mid-stream SSE error arrives, the HTTP response already has status 200.
+# We use this map to derive the correct status code for error classification.
+_SSE_ERROR_TYPE_TO_STATUS: dict[str, int] = {
+    "invalid_request_error": 400,
+    "authentication_error": 401,
+    "permission_error": 403,
+    "not_found_error": 404,
+    "request_too_large": 413,
+    "rate_limit_error": 429,
+    "api_error": 500,
+    "overloaded_error": 529,
+}
+
 
 _T = TypeVar("_T")
 
@@ -111,10 +125,24 @@ def __stream__(self) -> Iterator[_T]:
                     except Exception:
                         err_msg = sse.data or f"Error code: {response.status_code}"
 
+                    # Derive the correct status code from the error type when available.
+                    # The HTTP response is already 200 (stream started), so we need to
+                    # look at the error body to determine the right error class.
+                    error_response = self.response
+                    if is_dict(body):
+                        error_type = body.get("error", {}).get("type") if is_dict(body.get("error")) else body.get("type")
+                        mapped_status = _SSE_ERROR_TYPE_TO_STATUS.get(error_type or "", 0)
+                        if mapped_status:
+                            error_response = httpx.Response(
+                                status_code=mapped_status,
+                                headers=self.response.headers,
+                                request=self.response.request,
+                            )
+
                     raise self._client._make_status_error(
                         err_msg,
                         body=body,
-                        response=self.response,
+                        response=error_response,
                     )
         finally:
             # Ensure the response is closed even if the consumer doesn't read all data
@@ -231,10 +259,22 @@ async def __stream__(self) -> AsyncIterator[_T]:
                     except Exception:
                         err_msg = sse.data or f"Error code: {response.status_code}"
 
+                    # Derive the correct status code from the error type when available.
+                    error_response = self.response
+                    if is_dict(body):
+                        error_type = body.get("error", {}).get("type") if is_dict(body.get("error")) else body.get("type")
+                        mapped_status = _SSE_ERROR_TYPE_TO_STATUS.get(error_type or "", 0)
+                        if mapped_status:
+                            error_response = httpx.Response(
+                                status_code=mapped_status,
+                                headers=self.response.headers,
+                                request=self.response.request,
+                            )
+
                     raise self._client._make_status_error(
                         err_msg,
                         body=body,
-                        response=self.response,
+                        response=error_response,
                     )
         finally:
             # Ensure the response is closed even if the consumer doesn't read all data