GitHub Copilot model removals on 16 November: what to do

GitHub Copilot model deprecations announced on 15 October 2026 remove three models on 16 November 2026: Claude Opus 4.8, Claude Opus 5 and GPT-5.6 Terra. GitHub suggests Claude Opus 5.5 in place of both Opus models, and GPT-6.1 Sol or GPT-6 Luna in place of GPT-5.6 Terra.

The removal covers every Copilot experience GitHub lists: Copilot Chat, inline edits, ask and agent modes, and code completions. It is a Copilot product change, not a statement that these models leave their providers’ own APIs. One exception applies: individual Copilot subscribers on annual plans keep Claude Opus 4.8.

Sources checked on 10 November 2026; GitHub’s announcement had no changes as of that date. Availability can change; confirm the linked primary sources before acting.

GitHub Copilot model deprecations: what changes on 16 November

Removed model	GitHub’s suggested alternative	Deprecation date
Claude Opus 4.8	Claude Opus 5.5 (annual individual plans keep Opus 4.8)	16 November 2026
Claude Opus 5	Claude Opus 5.5	16 November 2026
GPT-5.6 Terra	GPT-6.1 Sol or GPT-6 Luna	16 November 2026

GitHub asks teams to move workflows and integrations to supported models before that date. Nothing has to be done to remove the old models afterwards; they simply stop being offered.

Inventory where the old models are used

Ask developers which model they pick in the editor, the CLI and other Copilot surfaces, and search team setup notes, onboarding pages and screenshots for the three names. A new starter following an old guide is the most common way a removed model keeps coming up in support questions.

Keep application code that calls Anthropic or OpenAI directly out of this list unless it actually goes through Copilot. Similar model names across products do not mean a shared schedule; each provider publishes its own notices.

Check what administrators need to do

For Copilot Business and Copilot Enterprise, GitHub enables the suggested alternatives automatically, unless an administrator turned off the global default or disabled a model explicitly. If your organisation did either, enable Claude Opus 5.5, GPT-6.1 Sol or GPT-6 Luna in the Copilot model policies; once enabled, they appear in the Copilot Chat model picker.

Ask someone with ordinary permissions to confirm what they see. An administrator’s account can show choices that policy hides from developers. Enterprise customers with questions are directed to their GitHub account team.

Test the replacement before changing defaults

Use a few representative repository tasks: an explanation, a debugging session and a patch that must keep existing behaviour. Compare the result, the number of follow-up prompts and any tool calls. The suggested alternative is GitHub’s recommendation, not a promise of identical behaviour, so record differences your team should know about.

If the team used GPT-5.6 Terra, try both suggested alternatives on the same tasks before choosing one as the shared default. Check in your Copilot settings whether usage accounting changes rather than assuming it stays the same.

Plan for the days after the switch

Publish a short internal note with the date, the chosen alternatives and where to report problems. For the first working days, collect concrete failures: the prompt, sanitised context, selected model and output. Separate model behaviour from network, account and client-version problems.

Do not tell people to work around policy with personal accounts. A migration is finished when developers can do their normal work on supported models, not when a new name appears in the picker.

Who needs to act?

Any team that selects Claude Opus 4.8, Claude Opus 5 or GPT-5.6 Terra in Copilot, and every Business or Enterprise organisation that turned off the global default for new models. Individual subscribers on annual plans who rely on Opus 4.8 keep it, but should still check the other two models.

The GitHub Copilot profile gives product context, and our comparison of AI coding assistants covers the wider choice. GitHub’s supported models page is the place to confirm current availability.

Sources and further reading

• Upcoming deprecation of selected GitHub Copilot models in mid-November — GitHub, 15 October 2026
• Supported AI models in GitHub Copilot — GitHub Docs

Image credits

Featured layout: Cloudsoft Zone, CC BY-SA 4.0. No product logos or screenshots are used.