Microsoft AI Outdiagnoses Doctors on Complex Cases

Microsoft's AI diagnostic system MAI-DxO correctly diagnosed complex medical cases 83% of the time in a simulation, compared to 36% for generalist physicians using reference materials, according to a study published in Science. The system coordinates multiple AI agents that question patients, order tests, and debate diagnoses. CEO Mustafa Suleyman called the result a step toward medical superintelligence. Best results came using OpenAI's GPT-5 and GPT-5.5. Microsoft is partnering with the Mayo Clinic on a healthcare foundation model planned for next year, and with Beth Israel Deaconess Medical Center to evaluate DxO in hospital settings.