Eight months after it doubled its valuation to $12 billion, OpenEvidence has done it again, only faster and with less noise. The Miami-based company behind the AI clinical search engine often called the ChatGPT for doctors has quietly closed a $250 million round at a $15 billion valuation, according to Business Insider. The bigger news is what the founders are reportedly doing alongside it: fielding acquisition interest, and considering a sale over the long march toward an IPO.
That would be a striking turn for a company that, as recently as January, was pitching investors on building "medical super-intelligence" as an independent, healthcare-only business.
A Fifth Round in Under Two Years
The new financing lifts OpenEvidence's valuation 25% above the $12 billion mark set by its Series D in January 2026, a round co-led by Thrive Capital and DST Global. Research firm Sacra and aggregated reports of the Business Insider story both name Andreessen Horowitz as a lead backer of the new round, with hospital systems also reported among the participants. Sources told Business Insider the deal came together without a formal announcement.
The pace of the company's fundraising has been unusual even by AI standards. Sequoia led a $75 million Series A at a $1 billion valuation in February 2025. GV and Kleiner Perkins co-led a $210 million Series B at roughly $3.5 billion that July. A $200 million Series C at about $6 billion followed in October, then the $250 million Series D at $12 billion in January. Counting the new round, OpenEvidence has raised more than $1 billion in about 19 months, from a cap table that also includes Nvidia, Coatue, Blackstone, Kleiner Perkins, and the Mayo Clinic.
The revenue has moved nearly as fast. Sacra estimates OpenEvidence reached about $300 million in annualized revenue by July 2026, up from $150 million at the end of 2025 and just $7.9 million at the end of 2024. At $15 billion, the new price works out to roughly 50 times that run rate. The product is free to verified clinicians. It makes money by selling pharmaceutical and medical device advertising, with Sacra reporting CPMs above $1,000 and only about 5% of ad inventory sold.
The Doctors Came First
OpenEvidence's leverage comes from its reach among physicians. In January, the company told Fierce Healthcare it was used daily by more than 40% of U.S. physicians across more than 10,000 hospitals and medical centers, and that it handled about 18 million clinical consultations in December 2025, up from roughly 3 million a month a year earlier. Sacra reports that on March 10, 2026, clinicians ran 1 million consultations on the platform in a single day.
Founder and CEO Daniel Nadler has credited early licensing deals with the New England Journal of Medicine, JAMA and its specialty journals, and the American Medical Association for building that trust. "We were the first to market with an AI product for doctors where it was grounded in the sources and references that they actually had been using for years and decades," Nadler told Fierce Healthcare in January. "We gave them the traditional content in a new interface."
Investors have leaned into that framing. "OpenEvidence is effectively the default operating system of medical knowledge in the United States today," Thrive Capital partner Kareem Zaki said when the Series D was announced.
Since then the company has moved well past search. It has shipped visit transcription, coding suggestions, a HIPAA-secure dialer, and a family of in-house models. It has also signed enterprise deployments embedded in Epic at Sutter Health, Mount Sinai, and Cedars-Sinai.
Why It Matters
Selling instead of going public would tell us something about where independent vertical AI companies stand. In January, Nadler was openly dismissive of the foundation labs moving into medicine. "I respect the hustle. Our view is that healthcare can't be a side hustle," he told Fierce Healthcare, adding that "a bet on OpenEvidence is a bet that focus wins."
Since then the competition has gotten much closer. OpenAI launched ChatGPT for Clinicians in April 2026, a free product for verified clinicians that copies OpenEvidence's bottom-up playbook and comes with a far bigger distribution base. Anthropic has pushed Claude into health systems and payers. Aggregated coverage of the Business Insider report says the pull toward a buyer is largely about compute, since training specialist medical models gets more expensive at the frontier and data center capacity is harder to secure. Nadler himself said in January that "the lion's share" of Series D money would go to training new models and compute.
A founder willing to listen to offers while raising at a higher price has strong negotiating leverage. Still, the scenario is hard to picture as anything other than a mega-deal. Few buyers can pay a premium on $15 billion. Those that can include the big AI labs, hyperscalers, EHR giants, and healthcare information incumbents such as Wolters Kluwer. For each of them, OpenEvidence's direct relationship with a large share of American doctors would be very hard to build from scratch.
What to Watch
Watch for who turns up as a bidder, and whether the founders decide the premium beats independence. The reported emphasis on compute points toward a hyperscaler or foundation lab rather than a traditional healthcare acquirer. Any deal would draw antitrust and clinical-safety scrutiny given how deeply the tool sits in U.S. medical decision-making. Meanwhile, the metrics that decide OpenEvidence's leverage are its ad sell-through, the launch of its paid, ad-free enterprise tier, and whether ChatGPT for Clinicians starts to dent daily physician usage. If OpenEvidence stays independent, its next round will probably be priced against those numbers. If it sells, the price will show what domain-specific distribution in healthcare AI is actually worth.
“I respect the hustle. Our view is that healthcare can't be a side hustle.”— Daniel Nadler, Founder and CEO, OpenEvidence