GitHub Copilot Retires Claude Opus 4.5, Gemini 3.1 Pro, and Four Other Models
GitHub CopilotGitHub Copilot deprecated six models on September 1, 2026 across every Copilot surface, including Copilot Chat, inline edits, ask and agent modes, and code completions. Retired models include Gemini 3.1 Pro, Claude Opus 4.5, Claude Opus 4.6, Claude Sonnet 4.5, Claude Sonnet 4.6, and Raptor Mini. GitHub Copilot recommends developers move to Gemini 3.6 Flash or 3.7 Flash, Claude Opus 4.7, 4.8, or 5, Claude Sonnet 5, and MAI-Code-1.1-Flash respectively, though Claude Sonnet 4.6 stays available to individual subscribers on annual plans. Enterprise and Business administrators need to enable the replacement models under Copilot policy settings before their teams lose access.
Key Takeaways
- GitHub Copilot retired six models simultaneously on September 1, 2026: Gemini 3.1 Pro, Claude Opus 4.5, Claude Opus 4.6, Claude Sonnet 4.5, Claude Sonnet 4.6, and Raptor Mini.
- The deprecation spans every Copilot surface, including chat, inline edits, ask and agent modes, and code completions, with no fallback to the old models after the cutoff.
- Claude Sonnet 4.6 is the one exception, staying available only to individual subscribers on annual plans.
- Business and Enterprise administrators must manually enable replacement models under Copilot policy settings, or their teams will lose model access entirely once the deprecated ones disappear.
- Any hardcoded model references in workflows, GitHub Actions, or Copilot Extensions built against a retired model ID will break and need updating.
- The retirement was announced 30 days in advance, on July 31, 2026, giving teams a window to test replacement models like Claude Opus 5 and Gemini 3.6 Flash before the deadline.
Six Models Retired Across Every Copilot Surface
Starting September 1, 2026, GitHub Copilot removed six AI models from all of its experiences, including Copilot Chat, inline edits, ask mode, agent mode, and code completions. The retired models are Gemini 3.1 Pro, Claude Opus 4.5, Claude Opus 4.6, Claude Sonnet 4.5, Claude Sonnet 4.6, and Raptor Mini. Once the cutover happened, none of these models remained selectable anywhere in GitHub Copilot, whether through the IDE extension, on Copilot's web chat, or through a Copilot Extension or workflow that calls a model directly by name.
Where to Migrate
GitHub Copilot pointed developers toward specific successors for each retired model. Gemini 3.1 Pro users should move to Gemini 3.6 Flash or Gemini 3.7 Flash. Claude Opus 4.5 and Claude Opus 4.6 are both replaced by Claude Opus 4.7, 4.8, or the newer Claude Opus 5. Claude Sonnet 4.5 gives way to Claude Sonnet 5, and Raptor Mini is succeeded by MAI-Code-1.1-Flash, the newer version of GitHub Copilot's in-house coding model.
An Exception for Annual Subscribers
Claude Sonnet 4.6 is also on the retirement list, but with one carve-out: individual GitHub Copilot subscribers on annual plans keep access to it so they are not left without a Sonnet-family model mid-contract. Everyone else, including Copilot Business and Copilot Enterprise seats and monthly individual subscribers, loses access to Claude Sonnet 4.6 along with the rest of the batch.
What Administrators Need to Do
For Copilot Business and Copilot Enterprise customers, the successor models are not automatically available. Administrators need to go to Settings, then Copilot, then Policies, and enable model access for each replacement before developers can select it in the model picker. Any workflow, GitHub Action, Copilot Extension configuration, or agent policy that names one of the retired models directly by its model ID also needs updating to reference a supported model. GitHub Copilot said the change had been flagged a month in advance, in a July 31 changelog post giving teams a 30 day window to test replacement models before the hard cutoff, and it directed enterprise customers with concerns to their account managers.