“ChatGPT for Doctors” Raises $250M Series D at $12B Valuation
OpenEvidence, a specialized AI-powered medical search engine, has raised $250 million in a Series D financing round led by Thrive Capital and DST Global, valuing the company at $12 billion and bringing total capital raised to roughly $700 million. The company operates a platform used across more than 10,000 US hospitals and care centers, with reported daily use by over 40 percent of practicing physicians nationwide.
The new funding is expected to go mainly toward research efforts, further model development, and the computing infrastructure needed to support them.
According to company-reported figures, the platform supported approximately 18 million clinical consultations in December 2025, up from around 3 million per month a year earlier. Over the course of 2025, more than 100 million US patients were treated by physicians using the system as part of clinical decision-making workflows.
Image credit: OpenEvidence
OpenEvidence is offered free to physicians and operates on an advertising-supported revenue model, reportedly reaching an annualized revenue run rate of about $100 million within a year of building its commercial organization. Because the system is trained exclusively on medical journals and curated medical data, this approach is intended to limit hallucinated outputs.
The search engine provides real-time, citation-linked answers to clinical questions, generated exclusively from peer-reviewed medical literature and professional guidelines. The platform has established direct licensing and data partnerships with major medical publishers and professional bodies, including the New England Journal of Medicine, the American Medical Association, the National Comprehensive Cancer Network, and the American College of Cardiology.
The Series D round follows a period of unusually rapid capital formation. In October 2025, OpenEvidence raised $200 million, roughly three months after its prior $210 million round, at a reported valuation of $6 billion, according to NYT. Around the same time, the company reported that its system became the first AI platform to achieve a perfect score on the United States Medical Licensing Examination (USMLE), a benchmark it positioned as evidence of domain-specific model performance rather than clinical autonomy.
OpenEvidence was founded in 2022 by Daniel Nadler, PhD, and Zachary Ziegler. Nadler previously founded Kensho Technologies, an AI and analytics company acquired by S&P Global in 2018, and later served as its CEO. The company is headquartered in Miami, with its primary AI research operations based in San Francisco.
From its inception, OpenEvidence was structured around exclusive licensing and data partnerships with major medical publishers, including the New England Journal of Medicine and the American Medical Association, and adopted a free-to-use, advertising-supported distribution model to accelerate uptake among verified clinicians.
Topic: AI in Bio
