GitHub Copilot retires four models today, with six more going dark October 19

GitHub Copilot's model lineup shrank today. Four models, Gemini 3.5 Flash, Gemini 3.6 Flash, Kimi K2.7 Code, and Claude Opus 4.7, were deprecated across every Copilot experience on October 2, 2026, GitHub announced in its changelog. The change covers Copilot Chat, inline edits, ask and agent modes, and code completions. If you had one of them pinned in a model policy or an agent profile, it stopped resolving this morning.

GitHub names one suggested replacement per model: Gemini 3.8 Flash takes both Gemini 3.5 and 3.6 Flash slots, Kimi K3 replaces Kimi K2.7 Code, and Claude Opus 5 replaces Claude Opus 4.7. For Copilot Business and Enterprise admins, the replacements are not always automatic. The changelog notes that administrators may need to enable access to the alternative models through their model policies in Copilot settings, and that once enabled, users will see the model in the Copilot Chat model selector.

This is wave one of two. On October 19, six more models go away: Gemini 3.7 Flash, GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini, and Grok 4.5, per GitHub's second changelog entry. Suggested replacements there are Gemini 3.8 Flash, GPT-5.6 Sol, GPT-5.6 Luna, and Grok 4.6. Under default model enablement, those replacements are automatically enabled for Business and Enterprise customers unless an admin turned off the global default or explicitly disabled the model.

The churn is the story. This is GitHub's third Copilot model retirement wave in under two months, and it keeps proving that a model name inside a coding workflow is a dependency with an expiry date, not a setting. GitHub does not publish prices on the deprecation notices, but independent analysis of GitHub's own per-token rate card found that most swaps stay flat while two get pricier: Kimi K3 lists at more than three times Kimi K2.7 Code's input price, and the GPT-5.6 Sol replacement for GPT-5.4 also costs more than the outgoing model, according to Pondero's migration guide. That is Pondero's read of GitHub's rate card, not GitHub's own claim.

What to do before October 19

For teams with heavy Copilot usage, the practical work is a sweep: search repo configs, workflows, agent profiles, and Copilot CLI settings for the ten retiring names, then rerun representative coding and review tasks against the replacements before the second deadline. GitHub has also designated GPT-5.3-Codex as a long-term support model, keeping it available for a year from its March 18, 2026 designation, which gives shops that want stability a boring option while the rest of the lineup keeps turning over. The alternative is to keep chasing deprecation notices in CI, and GitHub is not slowing down.