GitHub will deprecate Claude Opus 4.8, Claude Opus 5 and GPT-5.6 Terra across GitHub Copilot experiences on November 16, 2026. Its suggested replacements are Claude Opus 5.5 for both outgoing Opus models, and GPT-6.1 Sol or GPT-6 Luna for GPT-5.6 Terra.
The October 15 GitHub Changelog announcement includes one significant exception: Claude Opus 4.8 will remain available to individual Copilot subscribers on annual plans so those customers retain an Opus offering. GitHub says the deprecation of that model does not apply to those subscribers.
For platform engineers, the immediate task is to update affected workflows and integrations before the deadline and check whether organization policies allow access to the replacements. GitHub says no action is required to remove the outgoing models after deprecation.
Which Copilot models are being deprecated?
GitHub lists the following schedule and suggested alternatives:
| Outgoing model | Deprecation date | Suggested alternative |
|---|---|---|
| Claude Opus 4.8* | November 16, 2026 | Claude Opus 5.5 |
| Claude Opus 5 | November 16, 2026 | Claude Opus 5.5 |
| GPT-5.6 Terra | November 16, 2026 | GPT-6.1 Sol or GPT-6 Luna |
Claude Opus 4.8 remains available to individual Copilot subscribers on annual plans.
The announcement applies across all GitHub Copilot experiences, explicitly including Copilot Chat, inline edits, ask and agent modes, and code completions. Teams should therefore review their use of the affected models across those experiences when preparing the transition.
The replacement list is a migration recommendation from GitHub. The notice does not provide comparative benchmarks or explain how to choose between GPT-6.1 Sol and GPT-6 Luna. It also does not establish that the suggested models will produce equivalent results for an existing workflow. Engineers evaluating those alternatives should treat their own workflow checks as part of the migration decision.
The annual-plan exception is specific to Claude Opus 4.8
The exception matters because Claude Opus 4.8 appears in the retirement table while remaining available to a defined subscriber group. An individual subscriber on an annual plan should read that entry together with its qualification.
GitHub does not announce the same exemption for Claude Opus 5 or GPT-5.6 Terra. Nor does the notice extend the Claude Opus 4.8 exception to Copilot Business or Copilot Enterprise customers. Those customers have a separate consideration: whether their administrators have enabled the recommended alternatives.
How organization policies affect replacement access
Under default model enablement, GitHub says the suggested alternatives are automatically enabled for Copilot Enterprise and Copilot Business customers. That behavior has two qualifications: an administrator may have turned off the global default or explicitly disabled a model.
Where the global default is off, GitHub directs administrators to enable access to the alternatives through their model policies in Copilot settings. Once enabled, a model appears in the Copilot Chat model selector in supported GitHub Copilot experiences.
For administrators, this makes policy review a practical prerequisite to a user-facing migration. A replacement appearing in GitHub’s recommendation table does not, by itself, establish that users in every organization can select it. Teams should check their actual settings before directing developers to switch.
What to do before November 16
GitHub asks customers to update workflows and integrations to supported models before the deprecation date. A practical sequence follows from the notice:
- Identify workflows and integrations using Claude Opus 4.8, Claude Opus 5 or GPT-5.6 Terra, taking account of the individual annual-plan exception.
- Check access to the suggested alternatives, including the global default and any explicit model restrictions for Business and Enterprise customers.
- Evaluate the appropriate replacement in the affected workflows and complete the switch before November 16.
GitHub’s statement that no removal action is required addresses cleanup after deprecation; it does not replace its instruction to update workflows beforehand. Enterprise customers with questions or concerns are directed to their account team.
The deadline and replacement paths are clear. The remaining work for each team is to establish which model dependencies are affected, make the alternatives accessible under its policies, and verify that its chosen replacement meets the needs of the workflow.
