Microsoft AI says its diagnostic system, MAI-DxO, was more than twice as accurate as physicians on complex case studies published in The New England Journal of Medicine, in work published Thursday in Science. The system coordinates several AI agents that act like a panel of doctors: they question a simulated patient, order tests and debate a diagnosis. Microsoft also says it was 1.7 times more accurate than physicians on common emergency-department presentations, and reached diagnoses at a half to a third of the cost.

TechCrunch reports the system was right 83% of the time on the complex cases, versus 36% for primary care doctors and general internists working alone with reference materials. Specialists and physician teams, who usually handle cases this hard, weren't in the comparison. The study's own data suggests much of the gain comes from stronger underlying models (its best results used OpenAI's GPT-5 and GPT-5.5), and on emergency cases the orchestration added little over GPT-5.5 by itself. Microsoft AI CEO Mustafa Suleyman called it a step toward "medical superintelligence" and said Microsoft is training a health foundation model with the Mayo Clinic for release next year.