OpenAI is pushing stronger medical reasoning into the free ChatGPT tier: GPT-5.5 Instant now matches frontier Thinking models on its health evaluations, while 230 million users ask health and wellness questions each week.
OpenAI says GPT-5.5 Instant has pushed health responses close to its frontier Thinking models while reaching free ChatGPT users. The bigger signal is production data: flagged factuality issues in health answers fell 71% over two months.
OpenAI is moving from generic chat to a healthcare-specific workspace, and the timing is clear: 72% of physicians now report AI use in clinical practice. The new product is free to verified U.S. physicians, NPs, PAs, and pharmacists, and OpenAI says doctors rated 99.6% of tested responses safe and accurate across 6,924 conversations.
OpenAI released the GPT-5.3 Instant System Card on March 3, 2026. The document reports category-level disallowed-content scores, dynamic multi-turn safety testing updates, and HealthBench outcomes, including areas of both improvement and regression.