A retirement date is only the first part of a migration. The replacement must be supported, available to the right account, and fit the job.
October 20 update: the removal date has passed
GitHub’s October 19 confirmation retires six models across most Copilot experiences, including chat, edits, agent modes and completions. The notice says no action is required to remove the retired models.
This article previously described the deadline as upcoming and suggested earlier replacements. The table below uses the confirmed notice. It applies to GitHub Copilot; it does not establish availability in a model vendor’s own API.
Use the current replacement map
| Retired model | GitHub’s suggested alternative |
|---|---|
| Gemini 3.7 Flash | Gemini 3.8 Flash |
| GPT-5.5 | GPT-6.1 Sol |
| GPT-5.4 | GPT-6.1 Sol |
| GPT-5.4 mini | GPT-6 Luna |
| GPT-5 mini | GPT-6 Luna |
| Grok 4.5 | Grok 4.7 |
The updated destinations matter when an internal checklist was copied from an earlier announcement. Search configuration files and onboarding material, and check the current model picker.
Verify availability with the account doing the work
GitHub says Enterprise administrators may need to enable access to an alternative through model policies. Confirm that the replacement is enabled for the intended account and appears in the relevant Copilot interface.
A screenshot from an administrator’s account isn’t enough to confirm another user’s access. Keep the account, policy owner, requested model, and observed result in the migration record.
Retest one repeatable repository task
I would choose a known repair or review task with a clear expected result. Keep the source revision and permissions unchanged while checking the replacement.
- Search repository instructions, aliases, and automation for retired model names.
- Check the actual replacement available in each affected interface.
- Compare accepted results and tool-call failures.
- Measure total usage and human repair time.
- Update the migration record with the verified destination.
A suggested alternative is a support recommendation. It does not promise the same behavior, latency, or cost to complete the task. Don’t treat an older migration destination as permanent just because it once appeared in an official table.
The new model-policy API guide covers policy automation. The HydraFusion guide explains a separate routing workflow.
Read the sources and plan your next step
Which configuration outside the model picker still names a retired model?
Checked October 20, 2026. This is source-based reporting and analysis; proposed checks are not hands-on test results.
