OpenEvidence Says Its AI Reaches Two-Thirds of US Doctors

OpenEvidence says its AI medical search engine is now used by nearly two-thirds of the roughly one million physicians in the United States, with a source telling the Financial Times the ad-supported product is on track to generate between $400 million and $500 million in advertising revenue in 2026.

The Miami-based start-up, founded in 2022 by Daniel Nadler and Zachary Ziegler, reached a $15 billion valuation in September after a $250 million round that drew Andreessen Horowitz, Blackstone, Thrive Capital and Sequoia Capital. That roughly tripled the $12 billion valuation set in a January 2026 Series D of the same size. The platform is free to clinicians, sells pharmaceutical ads alongside its answers, and processes more than 42 million prompts a month.

Not every independent read of the product has been flattering. Research published in Nature showed OpenEvidence underperforming Google's Gemini and OpenAI's GPT on some clinical benchmarks, even as a Mayo Clinic accuracy study — Mayo is also an investor — landed favorably. The company has formal integrations with Mount Sinai Health System and Memorial Sloan Kettering Cancer Center; Paul Testa, NYU Langone's chief health informatics officer, said "clinicians were already using the tool as an independent resource."

OpenEvidence has withdrawn from the EU and UK, citing AI Act compliance costs. Our healthcare AI tracker has logged 65 clinical-AI alerts in the last 90 days, and adoption curves of this shape remain rare in the segment.