Upcoming deprecation of selected GitHub Copilot models in mid-October

GitHub will retire several Copilot models on October 19, 2026, affecting Chat, inline edits, ask, agent modes, and code completions. Users must switch to suggested alternatives like Gemini 3.7 Flash or GPT‑5.5. Enterprise defaults will auto‑enable replacements unless admins have disabled them, so update integrations promptly.