GitHub confirmed on October 19, 2026 that six models had been deprecated across most Copilot experiences, including chat, edits, agent work and completions. The company says this batch was first announced September 18. It is a separate dated retirement from the October 2 notice previously covered by AI Speed, and it should not be presented as a new model launch.
The notice gives specific alternatives, not a generic newest-model rule
GitHub maps Gemini 3.7 Flash to Gemini 3.8 Flash, GPT-5.5 and GPT-5.4 to GPT-6.1 Sol, GPT-5.4 mini and GPT-5 mini to GPT-6 Luna, and Grok 4.5 to Grok 4.7. These are GitHub’s suggested alternatives within Copilot, not an independent comparison of model quality.
The notice says no action is needed to remove retired models. Enterprise administrators may need to enable alternatives through model policies. Availability in a provider’s separate service does not establish that a particular Copilot account has access; verify the actual selector and effective organization or enterprise policy.
Related sources: GitHub: models deprecated October 19 ↗
Search for exact retired identifiers, including fallbacks
AI Speed’s practical assessment is to compare the six retired names against explicit selections in supported integrations, team instructions and evaluation records. A general announcement about retirement can be easy to acknowledge while one less-visible workflow continues requesting an obsolete option. Check both the primary model and any fallback named in that workflow.
Do not silently substitute the most capable-looking model everywhere. Keep the requested task, expected tool use and acceptance criteria attached to the change. For example, a code-editing workflow should still produce a reviewable diff and pass its tests; a repository explanation should still cite the correct files rather than merely sound more confident.
Keep completed retirements separate from later deadlines
The October 19 release also points readers toward other lifecycle notices. A future retirement is a planning item; this batch is reported as completed. Maintain separate dated records so a migration is not marked finished because a different deadline was addressed. The earlier October 2 article remains unchanged rather than being redated to create apparent freshness.
For Canadian teams, a useful handoff names the retired selection, the approved replacement, the accounts checked and the tests completed. Verify current plan and data-processing terms through official channels without assuming that a suggested replacement preserves every operational characteristic. This article reports the specific service lifecycle change; it does not claim lower cost, better speed or improved accuracy from the switch.
Sources and editorial method
We use the linked original statements and reports to distinguish documented facts from our analysis. Company announcements describe their authors’ plans and claims; they are not independent verification of future outcomes. This article is dated and will be revised if material evidence changes. Read our editorial standards and corrections process.
- GitHub: models deprecated October 19 ↗ — October 19, 2026 completed retirement; six named models, alternatives and policy-access caveat.
- GitHub Docs: enterprise model availability ↗ — Official access hierarchy; checked October 20, 2026.