GitHub will retire six models from GitHub Copilot on December 14, 2026, the company said in a changelog notice published November 13. The models will disappear from every Copilot surface: Copilot Chat, inline edits, ask and agent modes, and code completions.
The cull covers models from four providers: Anthropic, Google, xAI and Moonshot AI. GitHub named a suggested replacement for five of the six. The exception is Kimi K3, whose successor is still listed as “to be announced.”
Which models are leaving, and what replaces them
The headline swap for most developers is Claude Haiku 4.5, which moves to Claude Haiku 5.5, and Gemini 3.8 Flash, which moves to Gemini 4 Hydrogen, the fast model Google launched days earlier. GPTOnline covered the Gemini 4 Hydrogen launch on November 12. Gemini 4 Argon moves to Gemini 4 Carbon, Claude Fable 5 moves to Claude Fable 5.2, and Grok 4.6 moves to Grok 4.7.
One exception: Haiku 4.5 stays for some subscribers
Claude Haiku 4.5 will remain available to individual GitHub Copilot subscribers on annual plans, GitHub said, adding that the deprecation “does not apply to these customers.” Everyone else on Haiku 4.5 moves to Haiku 5.5.
What developers and admins need to do
GitHub urged users to switch before the deadline: “Please update your workflows and integrations to use the supported models before this date.”
For Copilot Business and Enterprise customers, the suggested replacements switch on automatically under default model enablement, unless an administrator turned off the global default or disabled a model. In that case, admins must enable the replacements by hand in Copilot model policies. Once enabled, the new models appear in the Copilot Chat model selector. GitHub said no action is needed to remove the retired models after December 14.
A rolling cleanup, not a one-off
The December round is the fourth wave of Copilot model retirements GitHub has announced since early October. An earlier notice, published October 15, removes Claude Opus 4.8, Claude Opus 5 and GPT-5.6 Terra on November 16, with Claude Opus 5.5 and GPT-6.1 Sol or GPT-6.1 Luna as the suggested replacements. The pattern is clear: as newer models ship, Copilot sheds older ones quickly, and teams that pin a model in their workflows need to track the changelog.
Why it matters
Copilot is one of the most widely used AI coding tools, so a six-model retirement touches a large share of working developers at once. Most users will be moved automatically, but teams with pinned models, custom agent modes or hard-coded model names in CI pipelines face a real deadline. The Kimi K3 gap is the one loose end: GitHub has not yet named a replacement, so Kimi users should watch the changelog before December 14.
