OpenAI gpt-3.5-turbo-instruct model retirement

Stopped workingSeptember 28, 2026Subscribe to OpenAIShare

Calls to model gpt-3.5-turbo-instruct fail since September 28, 2026. OpenAI shut down the model on that date, and requests using this model ID are no longer served.

The error you get

What OpenAI answers a call to gpt-3.5-turbo-instruct once the model is gone, as recorded from real responses:

HTTP 404

{"error":{"message":"The model `gpt-3.5-turbo-instruct` has been deprecated, learn more here: https://platform.openai.com/docs/deprecations","type":"invalid_request_error","param":null,"code":"model_not_found"}}

What to use instead of gpt-3.5-turbo-instruct

Move to gpt-5.6-terra, recommended by OpenAI. Because gpt-5.6-terra is not served on /v1/completions, moving requires more than changing an ID: update calls to Chat Completions (/v1/chat/completions) or the Responses API (/v1/responses), convert the prompt string to messages or input, and extract text from the returned message rather than choices[].text.

gpt-5.6-terra is not served on /v1/completions. Move the call to Chat Completions (/v1/chat/completions) or the Responses API (/v1/responses): the prompt string becomes messages or input, and the text comes back in a message rather than choices[].text.

In OpenAI's words

Shutdown date: 2026-09-28; Model / system: gpt-3.5-turbo-instruct; Recommended replacement: gpt-5.6-terra

OpenAI, Deprecations page

Facts

API: OpenAI api.openai.com
Model: gpt-3.5-turbo-instruct
Released: September 20, 2023 (models.dev)
Kind: Model retirement
Takes effect: September 28, 2026
Calls after that day: Fail
Source: Deprecations page
Last updated: November 5, 2026
Verified: November 6, 2026, against OpenAI's own pages

Questions

When does gpt-3.5-turbo-instruct shut down?

Calls to the model gpt-3.5-turbo-instruct on OpenAI stopped working on September 28, 2026.

What happens to calls after September 28, 2026?

They have failed since September 28, 2026.

What error does gpt-3.5-turbo-instruct return once it is shut down?

OpenAI answers HTTP 404: "The model `gpt-3.5-turbo-instruct` has been deprecated, learn more here: https://platform.openai.com/docs/deprecations". Send another model to fix it.

When was gpt-3.5-turbo-instruct released?

gpt-3.5-turbo-instruct was released on September 20, 2023, according to models.dev.

How do I find the calls this hits in my code?

Okapi reads your repository, finds the calls this change hits and opens a pull request with the fix. It never commits to your branches: every change comes as a pull request you review.

gpt-3.5-turbo-instruct on other APIs 2

No date Azure AI Foundry gpt-3.5-turbo-instructModel retirement Deprecated, no date
No date Azure OpenAI gpt-3.5-turbo-instructModel retirement Deprecated, no date

You fixed this one by hand.

Okapi opens the pull request with the fix before the next breaking change reaches your code.

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