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GitHub Copilot: Six Models Deprecated on October 19, 2026

GitHub CopilotView original changelog

GitHub deprecated six models across most GitHub Copilot experiences on October 19, 2026: Gemini 3.7 Flash, GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini and Grok 4.5. The removal covers Copilot Chat, inline edits, ask and agent modes, and code completions. GitHub points users to Gemini 3.8 Flash, GPT-6.1 Sol, GPT-6 Luna and Grok 4.7 as replacements, and notes that Enterprise administrators may need to enable them through model policies.

Key Takeaways

  • Six Copilot models were retired on October 19, 2026, namely Gemini 3.7 Flash, GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini and Grok 4.5.
  • The removal reaches Copilot Chat, inline edits, ask and agent modes, and code completions, so no major Copilot surface keeps the old models.
  • GitHub maps each retired model to a suggested replacement, including GPT-6.1 Sol for the two larger GPT models and GPT-6 Luna for the two smaller ones.
  • Enterprise administrators may need to enable the alternatives through model policies before users see them in the model selector.
  • The change was announced on September 18, 2026, giving roughly a month of notice before the models were removed.
  • No cleanup is required from users, but any workflow or integration that hard-codes a retired model should be updated to a supported one.

Six models retired in Copilot

On October 19, 2026, GitHub completed the deprecation of six models across most GitHub Copilot experiences. The retirement applies to Copilot Chat, inline edits, ask mode, agent mode and code completions. GitHub had announced the schedule on September 18, 2026, so this notice confirms that the planned removal has now taken effect.

Which models were removed and what replaces them

Each deprecated model has a suggested alternative from GitHub:

  • Gemini 3.7 Flash is replaced by Gemini 3.8 Flash.
  • GPT-5.5 is replaced by GPT-6.1 Sol.
  • GPT-5.4 is replaced by GPT-6.1 Sol.
  • GPT-5.4 mini is replaced by GPT-6 Luna.
  • GPT-5 mini is replaced by GPT-6 Luna.
  • Grok 4.5 is replaced by Grok 4.7.

Developers who had pinned one of these models in their workflows, saved prompts or integrations need to switch to a supported model. No action is required to remove the deprecated models themselves, since GitHub has already taken them out of the experiences listed above.

What Enterprise administrators should check

Copilot Enterprise administrators may need to enable access to the alternative models through the model policies in Copilot settings. GitHub recommends verifying availability in individual Copilot settings and confirming that the policy is enabled for the specific replacement model. Once a policy is enabled, the model appears in the Copilot Chat model selector in VS Code and on github.com.

GitHub Enterprise customers with questions or concerns are encouraged to contact their account manager.

Why it matters

Model retirements in Copilot happen on a regular cadence, and this round removes several older OpenAI models along with one Gemini and one Grok model. Teams that rely on a specific model for consistent output should review their defaults now, because a retired model can no longer be selected. GitHub's documentation on the models available in Copilot lists the current options.