OpenAI's upgraded ChatGPT health model now matches expensive AI systems and outperforms doctors on medical accuracy, with 71% fewer incorrect health statements.

What happened: OpenAI has upgraded ChatGPT with the GPT-5.5 Instant model, which matches the performance of the most expensive Thinking models on health-related benchmarks like HealthBench and HealthBench Professional. When compared to doctor-written answers, GPT-5.5 Instant scored higher in accuracy, clarity, and completeness across all five evaluation categories, reaching up to 89.9 percent on instruction following. The rate of incorrect health statements has dropped by 71 percent over the past two months. This model is now available to all free ChatGPT users, though with usage limits.

Why it matters: More than 230 million people use ChatGPT weekly for health-related questions—understanding lab results, preparing for doctor appointments, or navigating insurance. By delivering more accurate health information at no cost, this upgrade may reduce the spread of medical misinformation that users encounter when seeking preliminary health guidance online. OpenAI's network of over 260 doctors from 60 countries reviewed more than 700,000 model responses to achieve this improvement.

What to watch: GPT-5.5 Instant is available now to all free ChatGPT users, though with usage limits. OpenAI also offers specialized tools for healthcare professionals, including ChatGPT for Clinicians and OpenAI for Healthcare, which may serve a separate segment seeking professional-grade capabilities.