GitHub will deprecate three models across all GitHub Copilot experiences on November 16, 2026: Claude Opus 4.8, Claude Opus 5 and GPT-5.6 Terra. The retirement, announced in the GitHub Changelog on October 15, covers Copilot Chat, inline edits, ask and agent modes, and code completions — every surface where a developer can pick one of the three.
None of the three models is being withdrawn by the company that makes it. Anthropic’s own deprecation page lists Claude Opus 5 as active with a tentative retirement “not sooner than July 24, 2027”, and Opus 4.8 as active until at least May 28, 2027. What closes on November 16 is one route to them — the Copilot model picker — not the models themselves.
What Replaces Them, And The One Exception
GitHub’s suggested alternatives are Claude Opus 5.5 for both retiring Claude models, and GPT-6.1 Sol or GPT-6 Luna for GPT-5.6 Terra. Under default model enablement, the alternatives are switched on automatically for Copilot Business and Enterprise customers, unless an administrator has turned off the global default or explicitly disabled a model. Admins who have done that need to enable the replacements through the model policies in Copilot settings before the deadline.
There is one carve-out: Claude Opus 4.8 remains available to individual Copilot subscribers on annual plans, so they keep an Opus offering. The exception does not extend to Opus 5 or GPT-5.6 Terra, and it does not cover Business or Enterprise seats. GitHub says no action is required to remove the deprecated models once the date passes, and Enterprise customers with concerns should contact their account team.
The Third Wave Of A Rolling Cleanup
This is the third deprecation wave in six weeks. GitHub retired ten Copilot models between September 1 and October 2, including Claude Opus 4.5, Opus 4.6 and Sonnet 4.5 in the first wave, and Claude Opus 4.7, Gemini 3.5 Flash, Gemini 3.6 Flash and Kimi K2.7 Code on October 2. The practical risk sits in configuration rather than in the chat picker: any workflow, CI job, CLI script or extension that pins a model by name — in agent mode especially — will fail or silently reroute to a different default after November 16 unless it is updated first.
Our explainer on GitHub Copilot and its model line-up sets out how the picker reached this point, and our Copilot pricing guide covers which plans the change touches. Teams comparing routes to the same models can also weigh the direct-API options in our comparison of Claude Code, Cursor and Copilot.
Why It Matters
The central entity is the Copilot model picker, and its defining attribute is now churn: three waves in six weeks, with models disappearing from the picker while remaining alive at their makers. For platform teams, that turns model selection from a one-time choice into a maintenance obligation — pinned model names in pipelines are technical debt with a date attached. For Anthropic and OpenAI, the picker is a distribution channel they do not control, and GitHub’s consolidation onto Opus 5.5 and the GPT-6 family shows how quickly that channel can be re-pointed at a newer generation.
Background
GitHub Copilot, launched by Microsoft-owned GitHub in 2021 as an OpenAI-only tool, has become a multi-model product: its picker now carries models from Anthropic, Google and others alongside OpenAI’s, and GitHub has used rolling deprecations through 2026 to keep the list short as each lab’s release cadence accelerates. The November wave is the largest single consolidation of frontier models in that programme so far.
Source: GitHub Changelog (official, October 15, 2026) and Windows Forum.
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