OpenEvidence Becomes a Daily AI Tool for Over 40% of U.S. Physicians, Reaching a $12B Valuation
In just one year, OpenEvidence has moved from a fast-growing health AI startup to a tool used by a large share of U.S. physicians. The company builds an AI-powered medical search engine and chatbot exclusively for doctors and says its platform supported around 18 million clinical consultations in December alone—up from roughly 3 million per month a year earlier. According to the company, more than 40% of U.S. physicians now use the product daily across over 10,000 hospitals and medical centers, meaning an estimated 100 million Americans were treated last year by doctors using the tool.
That rapid adoption has been matched by aggressive fundraising. The startup recently raised $250m in a Series D round co-led by Thrive Capital and DST, doubling its valuation to $12bn. The round comes just months after a $200m Series C in October and a $210m Series B in July, bringing total capital raised over the past year to roughly $700m. Management says the new funding will largely go toward research and development, model training, and compute costs tied to its multi-agent AI architecture, as well as expanding content licensing partnerships.
The platform has positioned itself differently from many medical AI chatbots by grounding its models exclusively in licensed, peer-reviewed medical sources rather than the open internet. It has secured content partnerships with organizations such as the American Medical Association, The New England Journal of Medicine, and the full suite of JAMA journals, alongside major physician associations. This “copyright-friendly” approach, according to founder and CEO Daniel Nadler, has been central to building trust with clinicians who want conversational AI tools but remain cautious about accuracy and source quality.
Financially, the model appears to be gaining traction. The service is free for doctors and supported by advertising, and the company says it surpassed $100m in annual revenue last year. As new features roll out, including a HIPAA-secure communication tool for clinicians, the business is now framing its ambition more broadly: to become a kind of operating system for medical knowledge, powered by agentic AI systems that can specialize across different areas of clinical practice. Whether that vision holds up at scale remains to be seen, but the pace of adoption suggests AI tools have already become a routine part of how many doctors work.
Sources:
Fierce Healthcare
CNBC
A.M
