#model-lifecycle

GitHub Changelog said on April 3, 2026 that GPT-5.1 Codex, GPT-5.1-Codex-Max, and GPT-5.1-Codex-Mini were deprecated across all Copilot surfaces as of April 1. GitHub tells organizations to move workflows and model policies to supported models, with GPT-5.3-Codex named as the replacement.

OpenAI said on January 29, 2026 that ChatGPT would stop offering GPT-4o and older model options from February 13, 2026. GPT-4o, GPT-4.5, and o4-mini are being replaced by GPT-5, GPT-5 thinking, and o5-mini respectively.