GitHub Copilot retires nine models in four weeks, and opens an API to manage which ones your teams get

On 19 October 2026 GitHub deprecated six models across most Copilot experiences, including Copilot Chat, inline edits, ask and agent modes and code completions. The suggested replacements are GPT-6.1 Sol for GPT-5.5 and GPT-5.4, GPT-6 Luna for GPT-5.4 mini and GPT-5 mini, Gemini 3.8 Flash for Gemini 3.7 Flash and Grok 4.7 for Grok 4.5. GitHub had announced these retirements on 18 September 2026. Its notice says Copilot Enterprise administrators may need to enable the alternatives through model policies, and that nothing needs doing to remove the retired models.

On 15 October GitHub announced the next round for 16 November 2026, across all Copilot experiences: Claude Opus 4.8 and Claude Opus 5, both replaced by Claude Opus 5.5, and GPT-5.6 Terra, replaced by GPT-6.1 Sol or GPT-6 Luna. Claude Opus 4.8 stays available to individual subscribers on annual plans, so they keep an Opus option.

For Copilot Business and Copilot Enterprise, the November notice explains how replacements appear. Under default model enablement the suggested alternatives are switched on automatically, unless an administrator has turned the global default off or has disabled that model. Where the default is off, an administrator has to enable the replacements in the model policies before users see them in the model picker.

A model a team relies on can now disappear with about a month's notice, which is the gap GitHub gave for both rounds. Teams that have pinned a model in scripts, agent configurations or internal guidance will likely need to update them, and anyone who tuned prompts or review habits to one model's behaviour will be working with a different one afterwards.

The enterprises most exposed are the careful ones. An organisation that turned the default off so that only vetted models are available will not get the replacements automatically, so its developers can be left without the model they were using until someone approves the new one. That approval is also a decision about cost and data handling, so it is worth making before 16 November rather than on the day.

Also on 19 October 2026 GitHub made REST API endpoints for Copilot model policies generally available. GET and PATCH work at four levels: the enterprise, enterprise teams, enterprise apps and organisations. Enterprise policies can hand model decisions down to organisations, in what GitHub calls organisation mode, or to teams and apps, in enterprise teams mode.

GitHub's documentation sets out how those levels combine. An enterprise owner sets each model to enabled, disabled or delegated. Enterprise teams mode is an opt-in preview: switching to it deactivates organisation-level model settings, team settings only add to the enterprise baseline, and a user in several teams gets every model any of them enables. Models delegated to organisations become unavailable when an enterprise opts in, until they are enabled for specific teams.

Model access becomes something that can be managed like other access: kept in a reviewed configuration, applied by script and checked for drift. With retirements now arriving monthly, that likely matters more than it did when the model list changed a few times a year.

Enterprise teams mode lets access follow roles and training rather than organisation structure, for example higher-cost models only for teams that have been through training, which GitHub's documentation gives as an example. The opt-in has a regression risk that GitHub itself flags, so it is worth testing in a copy of the policy before switching.