Quick answer
OpenAI's API deprecations page lists September 28, 2026 as the shutdown date for gpt-3.5-turbo-instruct, babbage-002, davinci-002, and gpt-3.5-turbo-1106. It names gpt-5.6-terra as the recommended replacement for all four. Developers should check deployed configuration for those exact IDs and test their own workflows before migrating; a recommended replacement is not a guarantee of identical behavior.
The four API model IDs listed for September 28
OpenAI's deprecations page lists September 28, 2026 as the shutdown date for gpt-3.5-turbo-instruct, babbage-002, davinci-002, and gpt-3.5-turbo-1106. The notice is in the OpenAI API documentation and covers access to these model IDs through the API.
Sources: OpenAI
OpenAI names GPT-5.6 Terra as the recommended replacement
The same table names gpt-5.6-terra for each of the four retiring IDs. Treat this as OpenAI's migration recommendation, not proof that requests, outputs, or model behavior will be identical. Check the current model documentation and validate the change against representative prompts, parameters, and downstream expectations before relying on it in production.
Sources: OpenAI
Check deployed configuration and test the migration
Search application configuration, deployment variables, and scheduled jobs for each exact model ID—not just a user-facing model name. Identify the affected API call sites, update them to a supported model, and run representative tests that check output quality and any structured or tool-dependent behavior your application relies on. This checklist is editorial migration guidance; OpenAI's deprecation page does not guarantee compatibility for a particular integration.
Sources: OpenAI
Frequently asked questions
What readers usually ask
Which OpenAI API models have a September 28, 2026 shutdown date?
OpenAI lists gpt-3.5-turbo-instruct, babbage-002, davinci-002, and gpt-3.5-turbo-1106.
What replacement does OpenAI recommend?
The deprecation table names gpt-5.6-terra for all four IDs. Developers should still test their own integration because a recommended replacement does not establish identical behavior.
Does this mean the ChatGPT app is retiring these models?
The cited notice is an API deprecation notice about API model IDs. It does not announce a ChatGPT consumer-app change.
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