GPT-5.5 retired from Codex for ChatGPT sign-in

What changed

From October 14, 2026 at noon PDT, GPT-5.5 is retired from Codex for users signed in with ChatGPT. The replacement on Plus, Pro, Business, Enterprise and Edu is GPT-6.1 Sol (gpt-6.1-sol). On Free and Go it is GPT-6 Luna (gpt-6-luna) in the desktop app, where available. The OpenAI API and Codex sessions that use an API key are not affected.

Who it affects

Everyone using Codex with a ChatGPT sign-in (CLI, IDE extension, desktop app, cloud), and workspace admins. Not API-key users.

What to do

Replace gpt-5.5 in workspace defaults, saved model settings, managed configs, custom agents, scheduled tasks and scripts with gpt-6.1-sol (or gpt-6-luna on Free and Go).

Source: https://learn.chatgpt.com/docs/models#gpt-55-retirement