OpenEvidence is an AI medical search engine founded in 2022 by Daniel Nadler (Harvard PhD, former founder of Kensho/S&P Global) and Zachary Ziegler (Harvard ML researcher), and launched through the Mayo Clinic Platform Accelerate program. Headquartered in Miami, the company has raised over $700 million in venture funding — including a January 2026 Series D at a $12 billion valuation — from Sequoia, GV, Kleiner Perkins, Thrive Capital, NVIDIA, Blackstone, and others. The platform reports 430,000+ registered US physicians and 8.5 million consultations per month as of mid-2025, with content partnerships with NEJM, JAMA Network, and NCCN.
Despite the scale and funding, our evaluation identified concerns. OpenEvidence has marketed a 100% score on USMLE-type multiple-choice questions — a claim that independent researchers have challenged. A December 2025 pilot study by Jagarapu et al. found that Deep Consult achieved only 41% accuracy on complex medical subspecialty scenarios, with Quick Consult at 34%.
The platform is free but ad-supported, with revenue coming from pharmaceutical and healthcare advertising — a model physicians should be aware of when evaluating recommendations. OpenEvidence does not offer differential diagnosis generation or drug dosing tools of the kind found in higher-ranked platforms, and the company is currently involved in ongoing litigation with multiple competitors.