GitHub announced on November 13, 2026 that six models will stop working across every Copilot experience on December 14, 2026. The list covers Copilot Chat, inline edits, ask and agent modes, and code completions.
The six models and the suggested replacement
Retired model | Replacement suggested by GitHub |
|---|---|
Claude Fable 5 | Claude Fable 5.2 |
Claude Haiku 4.5 | Claude Haiku 5.5 |
Gemini 3.8 Flash | Gemini 4 Hydrogen |
Gemini 4 Argon | Gemini 4 Carbon |
Grok 4.6 | Grok 4.7 |
Kimi K3 | not announced yet |
There is one exception: Claude Haiku 4.5 stays available to individual Copilot subscribers on annual plans. For everyone else, the date is the same.
Who needs to act
In Copilot Business and Enterprise accounts with default model enablement turned on, GitHub enables the replacements automatically. The old model disappears from the picker and the new one is already there, with no work for the administrator.
Two groups are left with the work. The first is the organization that turned off default enablement or blocked a specific model, which is common in companies that only allow a model after a legal or security review. There, the replacement does not arrive on its own: someone has to enable it in the Copilot model policies, or the team loses the option it was using. The second is anyone who hard-coded the model name in workflows and integrations, such as agent instructions, shared repository settings or scripts. GitHub asks for those references to be updated before the date.
Kimi K3 is the awkward case: it leaves with no replacement named. Whoever picked that model for a specific reason will have to decide alone where to move.
What to do before December 14
For the administrator, the task is short. Check in the Copilot settings whether default enablement is on. If it is not, take the replacements through the same approval process the current models went through, early enough to finish before December 14. Then search repositories and agent instructions for the six model names and replace them.
Nothing needs to be removed: according to the announcement, the models go away on their own after the date.
For whoever chooses tools, the announcement is another reminder that the model inside a paid assistant has its own life cycle, set by the vendor with about a month of notice. That switching cost, which I discussed in a tool's cost includes the work to replace it, shows up here at a small scale, but repeatedly.
What the announcement does not say
The post does not say whether the replacements consume the premium request allowance at the same rate as the models being retired. For an organization that controls spending through that allowance, the difference can change the bill, and it is worth checking the models documentation before enabling the replacements.
There is also no date for a Kimi K3 replacement, and no detail on what happens to a call that still asks for a removed model after December 14.
If your company is weighing something similar, reach me on LinkedIn or WhatsApp.
