# Microsoft AI — Building Medical Superintelligence

- Company: Microsoft AI (microsoft.ai)
- Announced: 2026-10-22
- Category: research-paper
- Coverage: 2 outlets
- Announcement: no
- Group: covered
- Source: https://microsoft.ai/news/building-medical-superintelligence
- Record: https://forck.live/items/26803-building-medical-superintelligence
- Subject: MAI
- Models affected: MAI-DxO, GPT-5.5

Microsoft AI published research in Science on MAI-DxO, a diagnostic system that coordinates a panel of virtual physicians and outperformed physicians on step-by-step diagnosis. The company says MAI-DxO reached 83% accuracy on 304 complex NEJM cases, against 22% for physicians without reference resources and 36% with them. On more typical emergency-department cases from MIMIC-IV-ED, it scored 80% versus 47% for physicians. A cost-optimised configuration hit 81% accuracy on NEJM cases at less than half the cost of comparative systems, and Microsoft says no other human or AI approach was both more accurate and less costly across both datasets. The gains held when the evaluation was repeated with newer models, including GPT-5.5, without changing the orchestration method. Microsoft is open-sourcing SDBench for select NEJM cases, including the benchmark, Gatekeeper, Judge and cost-estimation code, and will run a prospective study with Beth Israel Deaconess Medical Center where patients interact with the system directly.

## Evidence

Verbatim from https://microsoft.ai/news/building-medical-superintelligence:

> On complex NEJM cases, MAI-DxO achieved 83% diagnostic accuracy. Physicians achieved 22% without external reference resources and 36% with them, making MAI-DxO about 3.7 and 2.3 times more accurate, respectively.

## Around this story

Outlets this record can name and link:

- Madrobot — Microsoft’s AI got 83% of medicine’s hardest cases right in a Science study, more than double the doctors’ score: https://madrobot.blog/2026/10/22/microsoft-mai-dxo-ai-diagnosis-beats-doctors-science-study-medical-superintelligence

## Follow-ups

- TechCrunch (reported, 22 Oct): Microsoft’s Mustafa Suleyman says its AI outperforms doctors on hard cases as he chases ‘medical superintelligence’ — https://forck.live/items/26821-microsoft-s-mustafa-suleyman-says-its-ai-outperforms-doctors-on-hard-cases-as

---

Record: https://forck.live/items/26803-building-medical-superintelligence
Catalogue: https://forck.live/llms.txt
Current issue: https://forck.live/feed.md