# GPT-5.5 Will Be Disabled in Codex on October 14: What to Choose Instead

> On October 14, 2026, OpenAI will disable GPT-5.5 in Codex for ChatGPT sign-ins on all plans. Which model to choose instead and how to change it in the CLI and app.

Source: https://ailoot.ai/blog/en/codex-gpt-5-5-retirement/
Canonical: https://ailoot.ai/blog/en/codex-gpt-5-5-retirement/
Language: en
Publisher: Ailoot (https://ailoot.ai/)
Translation: guide-079
Revision: sha256-36a7477f9685ed954d8d05236a97fa1576781686526f92ca5b928b0b65f72e41


<div class="aside" data-semantic="key-takeaway" role="note" aria-label="Key points in this section">

Key points

On October 14, 2026, GPT-5.5 will be retired from Codex, ChatGPT, and ChatGPT Work on all plans, including Enterprise and Edu. This retirement does not apply to the OpenAI API. The official replacement for Codex with ChatGPT sign-in is GPT-6 Sol on Plus, Pro, Business, Enterprise, and Edu; GPT-6 Luna in the ChatGPT desktop app on Free and Go, when the model is available. For complex coding work, OpenAI recommends the newer GPT-6.1 Sol when it is available to your account and client: it is not included at launch on Free and Go, and it is turned off in Enterprise and Edu until an administrator enables it.

</div>

Additional instructions for working with Ailoot are in the [documentation](https://ailoot.ai/docs/).



## Which GPT-5.5 access in Codex is being retired?

OpenAI gives the date and scope of the retirement on the official Codex models page:

<figure>
<blockquote>
<p>On October 14, 2026, GPT-5.5 will retire from ChatGPT, ChatGPT Work, and Codex on all plans, including consumer, Business, Enterprise, and Edu plans. This retirement does not apply to the OpenAI API.</p>
</blockquote>
<figcaption>— OpenAI, https://learn.chatgpt.com/docs/models</figcaption>
</figure>

Translation: On October 14, 2026, GPT-5.5 will be retired from ChatGPT, ChatGPT Work, and Codex on all plans, including consumer, Business, Enterprise, and Edu plans. This retirement does not apply to the OpenAI API.

In Codex, this affects sign-in with a ChatGPT account. If you authorize Codex with your own API key, access to models is determined by the OpenAI API organization and project associated with the key. This retirement does not affect them.

This is not the first such retirement. The same page says that `gpt-5.4` and `gpt-5.4-mini` were already retired from Codex with ChatGPT sign-in on August 31, 2026, and GPT-5.3-Codex-Spark was retired on September 14, 2026. The GPT-5.5 announcement appeared in the official “What’s New” roundup for the week of September 14–18, 2026.

Changing the model in Codex affects several places at once: the settings file, saved settings, and launch commands.



## Which Model Is the Recommended Replacement

The Codex models page lists replacements by plan:

<figure>
<blockquote>
<p>If you use Codex with ChatGPT sign-in, choose an available replacement before October 14:</p>
<ul>
<li>On Plus, Pro, Business, Enterprise, and Edu plans, choose GPT-6 Sol (<code>gpt-6-sol</code>) when available.</li>
<li>On Free and Go plans, choose GPT-6 Luna (<code>gpt-6-luna</code>) in the desktop app when available.</li>
</ul>
</blockquote>
<figcaption>— OpenAI, https://learn.chatgpt.com/docs/models</figcaption>
</figure>

Translation: If you use Codex with ChatGPT sign-in, choose an available replacement before October 14. On Plus, Pro, Business, Enterprise, and Edu plans, that is GPT-6 Sol (`gpt-6-sol`) when available. On Free and Go, it is GPT-6 Luna (`gpt-6-luna`) in the desktop app when available.

At the time of writing (September 30, 2026), the newer GPT-6.1 Sol is also available. In its recommended models section, OpenAI writes:

<figure>
<blockquote>
<p>For complex coding and agentic workflows, use GPT-6.1 Sol when available to your account and client. Use Luna for focused, repeatable tasks. [...] GPT-6.1 Sol offers near-Astra performance for complex work at a lower cost than Astra.</p>
</blockquote>
<figcaption>— OpenAI, https://learn.chatgpt.com/docs/models</figcaption>
</figure>

Translation: For complex coding work and agentic workflows, use GPT-6.1 Sol if it is available to your account and client. Luna is suited to focused, repeatable tasks. GPT-6.1 Sol delivers results close to Astra on complex work at a lower cost than Astra.

The condition “when available” matters here. According to the same page, access to GPT-6.1 Sol is rolling out in stages: at launch, it is included in Plus, Pro, Business, Enterprise, and Edu plans in Codex in the desktop app and CLI, as well as in ChatGPT Work on the web and in the mobile app. Free and Go are not included at launch. In Enterprise and Edu, GPT-6.1 Sol is turned off by default until an administrator enables it.

OpenAI calls GPT-6 Sol and GPT-6 Luna the replacements for GPT-5.5. GPT-6.1 Sol is a newer model that OpenAI recommends for complex coding work where it is already available. Availability depends on the rollout stage, sign-in method, and client; in an organization, it also depends on whether an administrator has enabled the model.

## How to Change the Model

How you change the model depends on where you use Codex.

**In an interactive CLI session (when working with Codex in the terminal),** the `/model` command lets you change the model or reasoning effort during a conversation. You can also specify a model at launch:

<figure>
<blockquote>
<p>In an interactive CLI session, use <code>/model</code> to switch models or adjust reasoning effort. You can also choose a model when you launch Codex with <code>--model</code> or its <code>-m</code> alias:</p>
</blockquote>
<figcaption>— OpenAI, https://learn.chatgpt.com/docs/models</figcaption>
</figure>

Translation: In an interactive CLI session, use `/model` to change the model or reasoning effort. You can also choose a model when launching Codex with the `--model` flag or its shorter form, `-m`.

The documentation gives an example for GPT-6.1 Sol:

```bash
codex --model gpt-6.1-sol
```

If you have a Plus, Pro, Business, Enterprise, or Edu plan, GPT-6.1 Sol is not yet available, and GPT-6 Sol is already available to your account and client, specify the official replacement `gpt-6-sol` with the same flag:

```bash
codex --model gpt-6-sol
```

The same flag also works in non-interactive mode. Example from the documentation:

```bash
codex exec -m gpt-6.1-sol "Review the current changes"
```

With the official replacement for your plan, the command looks like this:

```bash
codex exec -m gpt-6-sol "Review the current changes"
```

For Free and Go, OpenAI specifies GPT-6 Luna as the replacement specifically in the ChatGPT desktop app, so on those plans, select it there using the model switcher.

**In the ChatGPT desktop app (Work or Codex), ChatGPT Work on the web, and the IDE extension,** the model and reasoning effort switcher is below the message input field.

**Setting the default model through the settings file.** The ChatGPT desktop app, Codex CLI, and IDE extension all read the same `config.toml` file. To set the model, replace the existing `model` value or add this setting if it is not already present. Example from the documentation:

```toml
model = "gpt-6.1-sol"
```

For the official replacement on Plus, Pro, Business, Enterprise, and Edu:

```toml
model = "gpt-6-sol"
```

For Free and Go, where the replacement is GPT-6 Luna:

```toml
model = "gpt-6-luna"
```

OpenAI says that `gpt-6-luna` can be selected in the model switcher or in the saved configuration when the model is available.

If no model is specified in `config.toml`, Codex uses one of the recommended models. This does not remove the need to check places where `gpt-5.5` is explicitly selected: OpenAI asks users to replace it in the workspace’s default model settings, saved model settings, managed configurations, custom agents, scheduled tasks, launch scripts, and commands.

## Additional Check for Enterprise and Edu

If you are a workspace administrator or use Codex within an organization on an Enterprise or Edu plan, changing the model has an additional step. The official workspace model availability page warns:

<figure>
<blockquote>
<p>GPT-6 Sol and GPT-6 Luna are off by default in Enterprise workspaces at launch. An administrator must enable each model before members can select it.</p>
</blockquote>
<figcaption>— OpenAI, https://learn.chatgpt.com/docs/enterprise/workspace-model-availability</figcaption>
</figure>

Translation: At launch, GPT-6 Sol and GPT-6 Luna are turned off by default in Enterprise workspaces. An administrator must enable each model before members can select it.

GPT-6.1 Sol has its own rollout plan: in Enterprise and Edu, it is also turned off by default until an administrator enables it. Selecting a model in the local settings file does not grant access to it. Changing the workspace’s default model also does not grant access:

<figure>
<blockquote>
<p>Changing a default doesn't grant model access. Confirm that the replacement is available to the affected users on each client.</p>
</blockquote>
<figcaption>— OpenAI, https://learn.chatgpt.com/docs/enterprise/workspace-model-availability</figcaption>
</figure>

Translation: Changing the default model does not grant access to the model. Check that the replacement is available to the intended users in each client.

Model access (whether a user can select a model) and execution permissions (what an agent is allowed to do in the sandbox and which files and network destinations it can access) are set independently. The same page says:

<figure>
<blockquote>
<p>Model access determines whether a model is available to the authenticated user on a supported surface. Local permission profiles and managed requirements determine what an agent can do after a local run starts, such as which files it can change or which network destinations it can reach.</p>
</blockquote>
<figcaption>— OpenAI, https://learn.chatgpt.com/docs/enterprise/workspace-model-availability</figcaption>
</figure>

Translation: Model access determines whether a model is available to the authenticated user in a supported client. Local permission profiles and managed requirements determine what an agent can do after a run starts, such as which files it can change and which network destinations it can reach.

If you specify `gpt-6-sol` or `gpt-6.1-sol` in `config.toml` but the administrator has not yet enabled that model for your workspace, you will not be able to select it. A permission profile does not grant model access. Conversely, access to a model does not loosen the sandbox, confirmation rules, or network restrictions.

## What to Check Before October 14

1.  **Determine how you sign in to Codex.** If you sign in with a ChatGPT account (not a separate OpenAI API key) and use GPT-5.5, check your settings and choose an available replacement before the retirement.
2.  **Find explicit references to `gpt-5.5`** in `config.toml`, saved model settings, custom agents, scheduled tasks, launch scripts, and commands such as `codex exec -m` where the model is specified explicitly.
3.  **Replace it with a model available to you:** GPT-6 Sol or GPT-6 Luna, depending on your plan, or GPT-6.1 Sol if it is already available to your account and client. If you work in an organization, first check with the administrator whether the needed model is enabled in the workspace.
4.  **Try the replacement on a small, familiar task.** Seeing the model in the switcher alone is not enough for this check. OpenAI separately warns that reasoning levels do not match one-to-one across model generations and recommends starting with a lower level, then adjusting it based on the result.

## What You Cannot Conclude from This

The documentation does not promise that the new model will answer your specific tasks the same way as the old one. The models page points to official recommendations for choosing a model, where GPT-6.1 Sol is compared with Astra and Luna. Those guidelines do not replace testing on your project. This article presents OpenAI’s recommendations and does not include results from an independent model comparison.

The exact time when GPT-6 Sol, GPT-6 Luna, or GPT-6.1 Sol will become available for your specific plan and client is not guaranteed: according to OpenAI, availability depends on the rollout stage, sign-in method, and client. Selecting a model in the settings file also does not change the agent’s sandbox permissions; the official documentation treats these mechanisms separately.

If you are considering other tools, see the overview of [Codex alternatives in 2026](https://ailoot.ai/blog/en/codex-alternatives/). There are separate articles about choosing a model: [Which AI model to choose for a task](https://ailoot.ai/blog/en/ai-model-for-each-task/) and [GPT-6 Astra or Claude Fable 5.1: Which Should You Choose](https://ailoot.ai/blog/en/gpt-6-astra-vs-claude-fable-5-1/). GitHub Copilot has its own retirement announcement: it is a different product with a different model list and its own date. See the article [GitHub Copilot is retiring 6 models](https://ailoot.ai/blog/en/github-copilot-model-deprecation-2026/) for details.

<div class="section" role="doc-bibliography" aria-label="Sources">

### Sources

- [Codex models, section on the GPT-5.5 retirement (learn.chatgpt.com)](https://learn.chatgpt.com/docs/models): retirement date, plan coverage, replacements, GPT-6.1 Sol rollout, and ways to change the model
- [What’s New: preparing for the GPT-5.5 retirement (learn.chatgpt.com)](https://learn.chatgpt.com/docs/whats-new): entry in the roundup for the week of September 14–18, 2026
- [Workspace model availability (learn.chatgpt.com)](https://learn.chatgpt.com/docs/enterprise/workspace-model-availability): rules for administrators enabling models in Enterprise/Edu

</div>

Before October 14, find where `gpt-5.5` is explicitly selected and try the replacement on a small, familiar task.





For further work with models, you can go to [Ailoot](https://ailoot.ai/).

## Questions about GPT-5.5 Will Be Disabled in Codex on October 14: What to Choose Instead

### Does changing the default model grant my workspace access to it?

No. A model must be available to the account and client, and organization administrators may need to enable it. Local model settings and sandbox execution permissions control different things.

### Where should I check for an explicitly selected retired model?

Inspect config.toml, saved workspace settings, custom agents, scheduled tasks, and launch scripts or commands with an explicit model. After replacing it with an available model, test a small familiar task rather than relying on the switcher alone.


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