OpenEvidence Secures $210 Million Series B at $3.5 Billion Valuation, Reaching 40% U.S. Physician Adoption

CAMBRIDGE, MA – OpenEvidence, an artificial intelligence startup transforming medical knowledge access for clinicians, has announced a significant $210 million Series B funding round, valuing the company at $3.5 billion. The investment was co-led by Google Ventures and Kleiner Perkins, with participation from previous Series A leader Sequoia Capital, Coatue, Conviction, and Thrive, bringing OpenEvidence's total funding to over $300 million since its founding.

The company, founded by serial entrepreneur Daniel Nadler and Zachary Ziegler, has rapidly gained traction among U.S. physicians. According to Kleiner Perkins Managing Partner Mamoon Hamid, "the fact that 40% of all physicians in the United States log in daily to OpenEvidence’s software is a staggering signal of both trust and utility." This widespread adoption is further evidenced by the platform supporting over 8.5 million clinical consultations by verified U.S. physicians per month, representing a remarkable 2,000%+ year-over-year growth rate.

OpenEvidence addresses the critical challenge of information overload in healthcare, where medical research volume doubles every five years. Its AI-powered platform allows clinicians to "search once, skip the scavenger hunt, and surface the science in seconds," providing point-of-care answers grounded in the latest research. The company has forged strategic content partnerships with leading institutions, including the American Medical Association (JAMA) and The New England Journal of Medicine, ensuring access to gold-standard medical knowledge.

Alongside the funding announcement, OpenEvidence unveiled DeepConsult™, an AI agent purpose-built for physicians. This new offering provides PhD-level, medically-specialized AI agents capable of autonomously conducting advanced medical research and cross-referencing hundreds of peer-reviewed studies in parallel. Despite the significant computational cost, OpenEvidence is offering DeepConsult free to all verified U.S. clinicians.

Josh Coyne, an investor, lauded the company on social media, stating, "> @EvidenceOpen is an ‘N of 1’ company by almost any definition. Brilliant team. Life-saving product (literally) used daily. Viral organic growth (40% of all US doctors). It’s a privilege to get to work with startups like these." The company's unique free-for-clinicians, ad-supported business model has enabled its rapid organic growth, bypassing traditional hospital procurement processes.

OpenEvidence's growth comes at a time when the U.S. healthcare system faces significant challenges, including clinician burnout and a projected physician shortfall. Daniel Nadler emphasized the company's mission: "OpenEvidence’s commitment to building an AI copilot for clinicians is rooted in the belief that AI will be a force for good in the world, ultimately benefiting both healthcare professionals and the patients they serve." More than 100 million Americans are expected to be treated this year by a doctor who used OpenEvidence, underscoring its growing impact on clinical practice.