Minor changes to the name, such as using "GPT 5.5 mini" or "GPT-5.5 high" instead of "GPT 5.5", are acceptable when determining the release. Also, any major iteration of OpenAI models clearly expected to go beyond "GPT 5.4" counts. eg. "GPT 5.6" counts if they skip over GPT 5.5.
To count as released, the model must be accessible to some members of the public outside OpenAI (a closed beta doesn't count). If it is available through some API only this counts as a release.
See also:
/Bayesian/when-will-xai-release-grok-5
/Bayesian/gemini-35-google-release-date
/Bayesian/gpt55-openai-release-date (this market)
/Bayesian/when-will-openai-release-gpt6
/Bayesian/claude-46-anthropic-release-date
/Bayesian/when-will-anthropic-release-claude-qZd5QEQ225
/Bayesian/when-will-deepseek-release-v4
/Bayesian/when-will-deepseek-release-r2
/Bayesian/when-will-meta-release-llama-5-6h9UypqOdp
/Bayesian/when-will-alibaba-release-qwen-4
/Bayesian/when-will-moonshot-release-kimi-k3