OpenAI sets January 14, 2027 removal date for select GPT-4 series API models and points developers to gpt-6-luna

OpenAI notified developers on October 14 that certain GPT-4 series models will be removed from the API on January 14, 2027. The notice, as tracked by Releasebot, recommends gpt-6-luna as the replacement. The listing does not name every affected model, so teams should check the deprecation notice and the email sent to their organization to see which model IDs in their code are affected. The retirement lands as OpenAI pushes its newer lineup. Release notes from the past week show GPT-6.1 Sol as the default model in Codex 0.161.0, and an Ultrafast mode for GPT-6.1 Sol that OpenAI says delivers near-Astra intelligence at up to 8x the speed of Sol Standard. For builders with products still pinned to older GPT-4 endpoints, three months is short for anything with evals, tuned prompts or fixed-price contracts. A swap to a newer model changes output style, latency and cost, so regression tests and a pricing check are worth scheduling now rather than at the end of the year.