Expected: GitHub Copilot Will Retire Six Models on October 19
GitHub has set an October 19 cutoff for six models across Copilot, giving administrators and workflow owners a defined migration window.
Edited by Tyronne Panaino
GitHub announced on September 18 that six models are scheduled to leave all GitHub Copilot experiences on October 19, 2026. The change covers Copilot Chat, inline edits, ask and agent modes, and code completions, so it affects both interactive use and workflows that depend on a particular model choice.
The practical deadline matters most to administrators and teams that have pinned a model, disabled automatic model enablement, or built instructions around model-specific behaviour. GitHub has named a suggested alternative for every retiring option, but the actual cutover remains a future production event rather than a completed change.
What is known
The retirement list contains Gemini 3.7 Flash, GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini, and Grok 4.5. GitHub recommends Gemini 3.8 Flash for the first model; GPT-5.6 Sol for GPT-5.5 and GPT-5.4; GPT-5.6 Luna for GPT-5.4 mini and GPT-5 mini; and Grok 4.6 for Grok 4.5.
GitHub says the cutoff applies across all Copilot experiences and asks customers to update workflows and integrations before October 19. For Copilot Enterprise and Business accounts using default model enablement, the suggested alternatives are automatically enabled unless an administrator disabled the global default or explicitly disabled the replacement model. Administrators using stricter settings can enable an alternative through Copilot model policies.
That distinction prevents a simple one-size-fits-all migration plan. A user may see the recommended replacement automatically, while a managed organisation may need a policy change before the same option appears. Teams should therefore inventory pinned models, check their enablement rules, and test prompts or agent workflows against the replacement that matches their current tier.
What would confirm it
The announcement establishes GitHub's plan, not the completed retirement. Confirmation will come when the six models are no longer selectable or callable in each listed Copilot experience on October 19 and the recommended alternatives remain available under the documented policy conditions. A schedule or replacement change before then would require this expectation to be revised.
Status
Expectation. The date, affected models and migration guidance come from GitHub's official release note. Confidence is high in the announced plan, while execution is still pending.
Sources
Update note: Last reviewed 2026-09-22. We will revise this post if GitHub changes the schedule, replacement list or policy behaviour.
Sources
Drafted with AI assistance from source briefs; reviewed for citation completeness and label accuracy.