GPT-5.5 leaves ChatGPT, Work and Codex on October 14 — what changes and a migration checklist

Introduction

OpenAI’s ChatGPT Learn Models page confirms that GPT-5.5 leaves ChatGPT, ChatGPT Work, and Codex on October 14, 2026. The change applies to all plans — consumer, Business, Enterprise, and Edu. The sentence many teams need to read twice: this retirement does not apply to the OpenAI API. If you only call gpt-5.5 through the API, this cutoff date does not remove it.

If your team pinned GPT-5.5 in agents, scheduled tasks, workspace defaults, or Codex scripts that sign in with ChatGPT, the deadline is immediate: on October 14 the model leaves those surfaces. Below is what OpenAI published, what changes in practice, and a checklist for small and mid-sized businesses.

What OpenAI announced

The notice sits at the top of the Models page and in the September 14, 2026 changelog: on October 14, 2026, GPT-5.5 retires from ChatGPT, ChatGPT Work, and Codex on all plans. The same Models page describes GPT-5.5 as a previous-generation flagship and states that it remains available on the OpenAI API.

Replacement guidance is written mainly for Codex with ChatGPT sign-in (and reinforced on workspace model availability):

• On Plus, Pro, Business, Enterprise, and Edu, choose GPT-6 Sol (gpt-6-sol) when available.
• On Free and Go, choose GPT-6 Luna (gpt-6-luna) in the desktop app, also when available.

OpenAI asks you to replace gpt-5.5 in workspace defaults, saved model settings, managed configurations, custom agents, scheduled tasks, and scripts that select a model.

About ChatGPT Chat itself: the docs state that GPT-6 Sol and GPT-6 Luna are available in Work and Codex, and not in Chat. The retirement covers ChatGPT, but the named replacements are spelled out for Work/Codex. Open your product’s model picker and choose a model your workspace actually enables.

API versus ChatGPT and Codex: keep the cases separate

That does not guarantee the API keeps GPT-5.5 forever. It only means this October 14 product notice does not cut the API. Watch API deprecation docs for any future API date.

If you only use GPT-5.5 via the API, you do not need to change anything for this notice. If you use the same model in Codex with a ChatGPT account, you do.

Where to migrate (what OpenAI names today)

For Codex with ChatGPT sign-in, the Models page points to:

1. GPT-6 Sol (gpt-6-sol) — Plus, Pro, Business, Enterprise, and Edu, when available.
2. GPT-6 Luna (gpt-6-luna) — Free and Go in the desktop app, when available.

The same docs recommend GPT-6.1 Sol (gpt-6.1-sol) for complex coding and agentic workflows when your account and client have access. The changelog records GPT-6.1 Sol in Codex and ChatGPT Work (September 29, 2026) and GPT-6.1 Sol Ultrafast (October 8, 2026) for eligible plans. On Enterprise and Edu, admins may need to enable new models before they appear in the picker.

We do not invent availability: if the picker does not yet show gpt-6-sol or gpt-6.1-sol, use an available model OpenAI lists for your account and confirm with your workspace admin.

For GPT-6 context, see our GPT-6 Astra launch and Codex “28 days” posts. If you still rely on custom GPTs, that is a separate December deadline — covered in OpenAI retires custom GPTs.

Checklist that matters for October 14

1. Quick inventory. Search for gpt-5.5 in Codex config.toml, codex --model / codex exec -m scripts, custom agents, scheduled tasks, and workspace defaults.
2. Change the workspace default (Business/Enterprise/Edu) to an enabled model — typically gpt-6-sol once an admin enables it.
3. Update agents and automations. Scheduled tasks that still request GPT-5.5 may stop working after the cutoff date; do not count on a warning mid-run.
4. Test 3–5 critical prompts on the new model (refactor, PR review, extraction, one hard case).
5. Separate API from product. Backend API calls are not cut by this notice; Codex with ChatGPT sign-in is.
6. Confirm Free/Go. Official guidance points Free/Go users to Luna in the desktop app.
7. Tell the team today so nobody is surprised when the picker changes tomorrow.
8. Document the choice. Record model + reasoning effort used in main flows for the next migration.

What we are not inventing

• This notice gives no API removal date for GPT-5.5.
• We do not claim GPT-6 Sol or Luna already appear on every account — OpenAI writes “when available”.
• We do not mix the custom GPT December deadline with this model retirement on October 14.
• Codex 500K-context rumors are still not treated here as official changelog facts.

Conclusion

GPT-5.5 leaves ChatGPT, ChatGPT Work, and Codex on October 14, 2026. The API is excluded from this notice. For Codex with ChatGPT sign-in, OpenAI points to GPT-6 Sol (paid/business plans) and GPT-6 Luna (Free/Go on desktop) when available; GPT-6.1 Sol is the current recommendation for complex work where you have access. Inventory today, update defaults and scheduled tasks, and test critical flows before your team’s midday tomorrow.

Sources

• OpenAI ChatGPT Learn: Models — GPT-5.5 retirement
• OpenAI ChatGPT & Codex changelog (2026-09-14): GPT-5.5 retires October 14
• OpenAI ChatGPT Learn: Workspace model availability — prepare for GPT-5.5 retirement
• OpenAI ChatGPT Learn: What's new — prepare for GPT-5.5 retirement

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