OpenAI Announces ChatGPT Retirement for o3 and GPT-4.5
June 3, 2026
OpenAI is retiring older models in ChatGPT. The release notes say the API is unchanged, but teams still need model planning.
OpenAI announced in the ChatGPT release notes that o3 will be retired in ChatGPT on August 26, 2026, and GPT-4.5 on June 27, 2026. The important distinction is scope: the note says this affects ChatGPT, not the API. Still, teams that rely on ChatGPT model selection, training material, or prompt libraries need to update operational documentation.
Why it matters: Model lifecycle is now an operational risk. A workflow tied to one named model is fragile.
What teams should do now: Test prompts across models, update internal guidance, and document API-side model pinning strategies for critical workflows.
💡 In plain English
When a model disappears from ChatGPT, teams should know which workflows are affected.
Key Takeaways
- →o3 retirement in ChatGPT: August 26, 2026.
- →GPT-4.5 retirement in ChatGPT: June 27, 2026.
- →The API is not affected according to the note.
FAQ
Is this an immediate production risk?
Not as a security incident, but as an operations and governance issue.