What changed
OpenAI's ChatGPT & Codex changelog dated 14 September says GPT-5.5 will retire from ChatGPT, ChatGPT Work, and Codex on all plans on 14 October 2026. The notice explicitly covers consumer, Business, Enterprise, and Edu plans, and explicitly says the retirement does not apply to the OpenAI API.
For Codex sessions that use ChatGPT sign-in, OpenAI tells users to switch from `gpt-5.5` to `gpt-5.6-sol` before the cutoff. The migration guidance specifically calls out workspace defaults, saved model settings, managed configurations, custom agents, scheduled tasks, and scripts that still select GPT-5.5.
The API is outside this retirement
The scope matters because GPT-5.5 remains a live API model. OpenAI's current model page still lists `gpt-5.5` for the Responses and Chat Completions APIs, with a 1.05 million-token context window and the existing API pricing. The 14 October notice is therefore a product-surface retirement rather than a general shutdown of the model identifier.
Teams calling GPT-5.5 directly through the API do not have the same 14 October deadline under this announcement. Workflows that run through a ChatGPT-authenticated Codex session do, so hard-coded model selections in local configuration or automation should be treated as migration risks.
Why it matters
OpenAI introduced GPT-5.5 on 23 April as its flagship model for complex professional work and agentic coding. Retiring it from ChatGPT and Codex less than six months later shows how quickly model lifecycles can now turn over, especially for workflows that save a specific model name instead of relying on a supported default.
For Codex users the practical action is straightforward: locate explicit GPT-5.5 selections and test the same workflows on GPT-5.6 Sol before 14 October. That includes scheduled tasks and custom agents, where a stale model setting can fail without being visible in the main model picker.
What remains open
OpenAI has not announced an API retirement date for GPT-5.5 in this notice, and it does not specify a separate grace period after 14 October for the affected ChatGPT and Codex surfaces. Claims that GPT-5.5 disappears everywhere on that date go beyond the official scope. Any later API deprecation should be treated as a separate event and merged into this story when OpenAI publishes it.