companies

OpenEvidence

Free, ad-supported clinical AI search engine trained on peer-reviewed medical literature, used at the point of care by a large share of US physicians.

OpenEvidence was founded in 2022 by Daniel Nadler, a Harvard-trained economist who previously built and sold the financial analytics firm Kensho to S&P Global, together with machine learning researcher Zack Ziegler. The company is headquartered in Miami and built a medical question-answering tool trained specifically on peer-reviewed journal literature, using an ensemble of specialized models rather than one general-purpose LLM, with every answer traceable back to a cited source. Adoption has been unusually fast for a clinical software product: OpenEvidence says it is now used by roughly 40 percent of physicians in the United States, with an independent survey of over 1,000 doctors across 106 specialties finding OpenEvidence accounted for nearly half of reported clinical AI usage. The product is free for verified clinicians, supported instead by pharmaceutical advertising shown alongside answers, a model the company has been transparent about but that has also drawn scrutiny given the potential for advertiser influence on a tool doctors treat as a reference source. Funding has followed the usage curve: a $75 million Series A led by Sequoia in February 2025 valued the company at $1 billion, a $210 million round in July 2025 backed by GV and Kleiner Perkins pushed the valuation to $3.5 billion, and by January 2026 a further raise brought the valuation to roughly $12 billion, with investors including Thrive Capital, Nvidia, and Mayo Clinic's venture arm.

Founded

2022

Headquarters

Miami, United States

Sector

applications