1,086 Instruction Revisions: What Associations Stand to Lose When Custom GPTs Retire on 11 December
Across 82 associations and nonprofits, teams revised their AI assistants’ instructions 1,086 times. OpenAI’s migration carries the instructions across, but not the sharing, the custom actions, or the model.
NEEDHAM, Mass. — November 5, 2026 — With the custom GPT retirement set for 11 December, associations that built member assistants on OpenAI’s custom GPTs need to migrate them, and new figures from CustomGPT.ai suggest the part most worth protecting is the part teams worked hardest on. Across 75,200 member questions put to AI assistants at 82 associations and nonprofits, those organizations made 1,086 revisions to their assistants’ instructions: the brief that governs how an assistant answers, what it covers, and what it does when it is unsure.
OpenAI will retire custom GPTs on 11 December 2026, replacing them with plugins. Its own migration guidance is specific about what survives the move and what does not. Instructions become a skill, knowledge files become reference files, and existing conversations stay accessible after retirement. But custom actions stop working until they are rebuilt, the model the GPT used is not carried over, and a migrated plugin starts private. People who could use a shared GPT do not automatically get access.
For a membership organization, that last point is not a technicality. An assistant shared with several thousand members starts out private after migration, and someone has to share it again. In a managed workspace OpenAI can prefill the original audience, but it still has to be reviewed and saved.
Many association assistants do more than answer from a document. If one sits behind a member login, links out from a portal, or looks up renewal dates, CE credits or past sessions in the association management system, each of those connections is something the organization set up, and each needs checking after the move.
“Associations rewrote their assistants’ instructions over a thousand times. That’s where the real work is: figuring out what it should answer, what it should pass to staff, and what to say when it doesn’t know. That work belongs to the association, no matter where it runs,” said Alden Do Rosario, CEO and co-founder, CustomGPT.ai.
What the data shows
- 82 associations and nonprofits, 75,200 member questions, twelve months to 22 October 2026.
- 1,086 revisions to assistant instructions across those organizations.
- Seven in ten assistants run on instructions the organization wrote itself.
- Three in four answer only from the organization’s own content.
- Assistants are set to decline rather than guess when their content does not cover a question.
What associations should do before 11 December
- Export the instruction text. It is the organization’s own work and the hardest piece to rebuild.
- List every custom action. Those break on migration and need rebuilding as an app or a custom MCP server.
- Write down who the assistant is shared with. Sharing does not carry over.
- Retest after migrating, as OpenAI advises. A migrated plugin may respond differently.
The full checklist is in What happens to your association’s custom GPT on 11 December 2026.
CustomGPT.ai is one option among several for organizations that want an assistant they control. Our comparison of ChatGPT and member-facing AI for associations is at customgpt.ai/chatgpt-vs-member-ai-associations
About CustomGPT.ai
CustomGPT.ai is a no-code platform for building custom AI agents on an organization’s own content. Agents answer from the content they are given and decline when it does not cover a question, rather than guessing. CustomGPT.ai is used by associations, nonprofits and businesses to answer member, customer and staff questions. Learn more at customgpt.ai.
CustomGPT.ai is not affiliated with OpenAI, and is not a migration path provided or endorsed by OpenAI.
Media contact: press@customgpt.ai
