Your Custom GPT Options on ChatGPT Plus After December 11

When an office building changes hands, the big tenants hear about it first. The law firm on the top floor gets a meeting, a transition plan and, if it pushes, a few extra months on its lease. The person renting a small office month to month on the second floor gets a letter taped to the door with a date on it.

Nobody's being cruel. That's how notice works when some tenants have an account manager and some just have a key.

If you pay for ChatGPT Plus and built a custom GPT or two for your agency, you're on the second floor. OpenAI is retiring custom GPTs on December 11. Enterprise workspaces got admin notices, a migration schedule and, for some, a deferral into February. Most of what's been written about the change, including a good share of OpenAI's own help pages, is written for the top floor. This one is for you.

What actually applies to a Plus account

Here's where OpenAI's help pages stand at the end of September.

New GPT creation and publishing aren't available on personal accounts, which OpenAI lists as Free, Go, Plus and Pro. That's already true today, so if you were planning to build one more GPT before December, that door is closed.

The GPTs you already have keep working until retirement. Editing one "continues to require an eligible subscription," and OpenAI doesn't say which subscriptions count. Open your GPT's configuration this week and see whether you still can, before you plan around changing it.

December 11 is the retirement date in OpenAI's newest FAQ, which says the change affects all plans, though older OpenAI pages still call it the Enterprise date and every date is subject to change. Watch for a notice on your own account. OpenAI's migration button, Migrate to plugin under My GPTs, shows up "when migration is available for your account." What it produces is a skill, and OpenAI lists skills in ChatGPT for Business, Enterprise, Healthcare and Edu workspaces. Personal plans aren't on that list.

Put those together and there's a gap. The button that moves your GPT turns it into something your plan doesn't list. OpenAI may close that gap before December. It hasn't said it will, and I wouldn't plan around a promise nobody has made.

One more case worth naming. If the GPT you lean on was built by someone else, say one you found in the GPT Store, you can't migrate it at all. OpenAI is plain that permission to use someone else's GPT doesn't give you permission to move it. Watch for a notice on the GPT itself, and ask whoever built it what replaces it.

Get the instructions out first

Whichever way you go, the first job is the same, and it's the one people put off. Open each GPT you built, copy the full instructions into a document, and find the original copies of any files you uploaded to it. Write down the conversation starters too.

Do it now rather than in December. After the 11th there's nothing left to open, and if your plan no longer lets you into a GPT's configuration, your own notes and original files are all you'll have to rebuild from. If you want help deciding what each piece of a GPT should become, How to Migrate a Custom GPT to a Skill walks through the sorting.

Four ways forward, none of them wrong

Keep it on the plan you already pay for, as a Project. Projects are available on every ChatGPT plan, including Plus. You can give a project its own instructions and upload reference files, up to 25 per project on Plus and Go. Paste the GPT's instructions in, add its templates, and you've kept most of what the GPT did with no new bill. What you give up is the one-click assistant you could hand to someone else. You'll open the project and start a chat inside it instead. It works well for one or two jobs and gets cluttered past that, because every set of instructions lives in one place.

Move to a ChatGPT Business seat. Business workspaces have skills, so this is the path where OpenAI's migration button does what it was built for. You can create a skill in a chat, in an editor or by uploading one, and share it with people in your workspace. The cost is a business subscription and a workspace to manage. If you go this way, confirm how your existing GPT gets into the new workspace before you count on the button. OpenAI's FAQ tells anyone with several accounts to check where each GPT was created.

Move the procedure to Claude. Claude offers skills on every plan, including the free one, and they need code execution turned on. You can build a skill by uploading a finished one, and the standing facts about your agency go in a Claude Project. The cost can be nothing, or a second subscription if you need more room, plus learning a new tool. What you get is a skill in an open format that other tools can read, so the work isn't tied to one vendor the next time something retires.

Rebuild it as a Gemini skill. Google is turning Gems into skills starting in November 2026 for personal Google accounts. Its help page says skills are available without a Google AI subscription for anyone 18 or over on a personal account with Keep Activity on, and you can upload a SKILL.md file made on another platform through the Gemini web app or the Mac app. Grade that one carefully. Google's own pages disagreed about whether creating a skill needs a paid plan as recently as last week, and building one inside Gemini Spark does need Pro or Ultra. Check the page on the day you build.

If client health information is involved

For a Medicare agent, this question settles more than the price does. OpenAI's list of HIPAA-eligible products covers offerings like ChatGPT for Healthcare and Enterprise with a regulated workspace, and it requires a signed business associate agreement. Personal plans and ChatGPT Business aren't on that list.

Whatever you move to, check what that plan says about a BAA before a single beneficiary's details go into it. Check your carriers' and your FMO's rules too, because they outrank anything you decide on your own.

How to choose

Start with how the GPT gets used. If it does one job you run a few times a week, a Project on the plan you already have is probably enough, and it costs you nothing but an afternoon.

If other people at the agency need to run it the same way every time, you want a skill, and the choice is between a Business seat and Claude. Pick the one your team will actually open. And if the GPT touches client data, let the BAA question make the call before anything else does.

When a building sells, the tenants who come through it best are usually the ones who packed the boxes they cared about before the letter went up. Copy those instructions out this week, and December 11 becomes a date you planned for.

If you'd like a clearer picture of where your agency stands with AI before you pick a platform, the AI Adoption Reality Check takes about five minutes. I read every one and write back within two days.

Frequently asked questions

Will my custom GPT stop working before December 11? OpenAI says existing GPTs remain usable until retirement, and December 11, 2026 is the standard date. The dated record, including the February deferral that applies only to some Enterprise workspaces, is in OpenAI Is Retiring Custom GPTs. Here's the Official Record.

Can I still build a new GPT on ChatGPT Plus? No. OpenAI's help page says new GPT creation and publishing aren't available on personal accounts, and it names Plus alongside Free, Go and Pro.

Is there a free way to keep my GPT's instructions? A Project on ChatGPT's free plan holds instructions and up to five files per project. Claude's free plan includes skills too. On Google's side, the Gemini help page says skills work without a subscription on a personal account, though that's worth checking the day you rely on it.

Will I lose my old conversations with the GPT? OpenAI's migration doesn't carry existing conversations across, but its FAQ says existing conversations with custom GPTs remain accessible after retirement, and you don't need to do anything to preserve them.