Open Evidence

OpenEvidence is an American artificial intelligence company that develops a medical search engine and generative AI assistant for healthcare professionals, providing point-of-care clinical decision support. The product lets clinicians enter clinical questions or patient case details and returns synthesized answers grounded in peer-reviewed medical literature, with citations and follow-up suggestions. The platform is HIPAA compliant and is free to U.S.-based clinicians, who must verify their National Provider Identifier (NPI) number through the NPPES registry to register.

The platform's answers are grounded in licensed content rather than the open internet. OpenEvidence describes itself as an official AI partner of The New England Journal of Medicine, JAMA and the JAMA Network specialty journals, Nature and the Nature Portfolio, and Cochrane Systematic Reviews, and as having an official AI collaboration with the National Comprehensive Cancer Network covering NCCN Guidelines treatment algorithms. Other content and organizational partners cited include the American Medical Association, the American Academy of Family Physicians and the American College of Emergency Physicians.

Beyond search, the product line has expanded into agentic and workflow features, including DeepConsult (an AI agent for physicians released broadly in July 2025), EvidenceGrade (surfacing the strength of cited evidence), a specialty oncology model incorporating ASCO guidelines, a HIPAA-secure Dialer communication tool, patient messaging, fax, ambient note generation with configurable "Voices," automated CPT/E-M/ICD-10 coding suggestions, reusable prompt "Dotflows," patient handout "Take-Homes," and a continuing education/MOC credit platform.

Founding story

Founded in 2022 by Daniel Nadler, a Harvard PhD, and Zachary Ziegler, a Harvard machine-learning researcher and PhD student, to address the difficulty physicians face in keeping up with rapidly growing medical literature. Nadler previously founded Kensho Technologies, acquired by S&P Global in 2018 for about $700 million, and invested $10 million of his own money into OpenEvidence.

Business model

Access to the platform is free for verified U.S. clinicians; revenue is generated from advertising. Pharmaceutical and medical device companies purchase five-second video ads within the application, delivered contextually based on the physician's search query. Management states most ad inventory remains deliberately unsold to preserve the user experience.

Advertising-supported. The company reported topping $100 million in annual/annualized revenue in 2025, and the CEO stated revenue could reach roughly $1 billion if all available ad inventory were sold.

Traction

The company reports use across more than 10,000 U.S. hospitals and medical centers and daily use by more than 40% of U.S. physicians. Monthly verified-physician consultations grew from roughly 358,000 in July 2024 to over 8.5 million in July 2025 and about 18 million in December 2025, versus about 3 million a month a year earlier. Registered U.S. physicians rose from more than 430,000 (July 2025) to 760,000 (December 2025), with roughly 65,000 new verified clinician registrations per month reported in mid-2025. The company states more than 200 million AI-powered clinical consultations have been supported to date and that over 100 million Americans are treated annually by a clinician using the platform.

Latest developments

Following the January 2026 Series D, the company said it would spend heavily on R&D and compute for its multi-agent architecture, additional content licensing, and specialist "medical super-intelligence" models, a thesis Nadler presented at the J.P. Morgan Healthcare Conference. The announcements page lists 2026 partnerships and launches including Cedars-Sinai (agentic, patient-aware clinical intelligence), NewYork-Presbyterian/Columbia/Weill Cornell, the American Academy of Pediatrics, Boston Children's Hospital, OneOncology, Springer Nature, the Los Angeles County Department of Public Health, the American Academy of Ophthalmology, the Society for Neuro-Oncology, the Society of Surgical Oncology, the Anticoagulation Forum and JOMI, plus product releases such as EvidenceGrade, a CE/MOC education platform, Patient Take-Homes, Coding Intelligence, Voices, Messages, Fax and Dotflows.