ST-2026-248 · AI models & platform lifecycle
GitHub Copilot deprecates six selected models on 19 October 2026
GitHub will deprecate Gemini 3.7 Flash, GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini and Grok 4.5 across all Copilot experiences on 19 October 2026, with GitHub-published alternatives for each model.
Previous state
Gemini 3.7 Flash, GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini and Grok 4.5 remained available across GitHub Copilot experiences before the announced deprecation date.
Current state
On 19 October 2026, GitHub will deprecate the six selected models across all Copilot experiences and directs users to Gemini 3.8 Flash, GPT-5.6 Sol, GPT-5.6 Luna and Grok 4.6 as the corresponding alternatives.
Affected users
Who needs to care
GitHub Copilot users, workflows and integrations that select any of the six deprecated models, plus Business and Enterprise administrators who govern model availability.
Required response
What to do
Update affected workflows and integrations to the GitHub-published alternative models before 19 October 2026, and have Business or Enterprise administrators verify that the required alternatives are enabled under their model policies.
Evidence boundary
What the source does not prove
GitHub proves the deprecation date, affected model set, suggested alternatives and default enablement rule for Business and Enterprise. It does not prove that every customer administrator has enabled an alternative or that every workflow has migrated.
Lifecycle history
Dated event sequence
- GitHub announces selected-model deprecations
GitHub published the affected model set, suggested alternatives and 19 October 2026 effective date.
- Deprecation takes effect
The six selected models are scheduled to be deprecated across all GitHub Copilot experiences.
Evidence ledger
First-party sources
- 01GitHub Changelog — Upcoming deprecation of selected GitHub Copilot models in mid-October
Official GitHub Copilot model-lifecycle and migration authority · 2026-09-18
Open official source ↗