OpenEvidence is currently the most widely used AI clinical tool in the US by reported adoption. Over 757,000 verified physicians have signed up, and the company reports that more than 40% of US physicians log in daily across 10,000+ hospitals and medical centers. As of January 2026, usage reached over 20 million clinical consultations per month, up from roughly 3 million per month one year earlier.
Founded in 2022 by Daniel Nadler (Harvard PhD, former founder of Kensho/S&P Global) and Zachary Ziegler (Harvard ML researcher), OpenEvidence launched through the Mayo Clinic Platform Accelerate program. The company moved its headquarters from Cambridge, Massachusetts to Miami, Florida in 2025. It closed a $250 million Series D in January 2026 at a $12 billion valuation, bringing total funding to over $735 million. Reported annual revenue reached $100 million by January 2026.
For clinicians, the practical value is speed and citation coverage. The partnership network includes NEJM, JAMA and all eleven JAMA specialty journals, NCCN, ACC, AAFP, ACEP, ADA, AAOS, AAOHNS, and 300+ medical journals plus FDA and CDC sources. Quick Consult supports rapid lookups; Deep Consult runs longer synthesis for complex questions. The app includes a built-in dialer and native iOS/Android clients with Home Screen and Lock Screen widgets.
Tradeoffs are important. OpenEvidence has reported a 100% score on USMLE-type questions, but a December 2025 preprint by Jagarapu et al. reported lower accuracy on complex subspecialty scenarios (41% for Deep Consult, 34% for Quick Consult), while noting similarly low performance across models on that dataset. The product is ad-supported, and it still does not provide differential diagnosis generation or drug dosing tools. Teams that need broader bedside decision support may need a companion tool.