OpenEvidence has reached a reported $15 billion valuation after raising another $250 million. Andreessen Horowitz and Byers Capital led the round, which founder and CEO Daniel Nadler confirmed to Becker's Hospital Review in September 2026. [1]
The company gives clinicians a tool for answering medical questions using published research. Its core service is free for verified U.S. clinicians. [2][3]
That combination deserves attention: a free product for doctors, a business funded by advertisers, and investors valuing the company at $15 billion.
Understanding the valuation starts with the job OpenEvidence does and how often clinicians have a reason to use it.
What OpenEvidence does
OpenEvidence searches medical research and synthesizes answers for healthcare professionals. A clinician enters a question, and the tool produces a response grounded in medical literature, with citations to supporting sources. [2][4]
You can think of it as a way to search and organize medical evidence around a specific question. Its usefulness depends on whether the answer and underlying sources help the clinician make a decision.
OpenEvidence's terms describe the service as educational and informational. They say it supports a healthcare professional's independent judgment and does not substitute for that judgment. The service is intended for healthcare professionals acting in their professional capacity, rather than patients using it directly. [2]
For patients, that distinction matters. OpenEvidence can help your doctor investigate a question. Your doctor still has to decide how the information applies to you.
Who built OpenEvidence
Daniel Nadler and Zachary Ziegler founded OpenEvidence in November 2021, according to the company's own court filing. Nadler serves as CEO. Ziegler serves as chief technology officer and previously studied machine learning as a Harvard doctoral student. [5][1][6]
Nadler had already built an AI company for another profession. He founded Kensho in 2013 to develop analytics for financial institutions. S&P Global announced an agreement to acquire Kensho in March 2018. OpenEvidence applies a related idea to medicine: help professionals work with a body of information too extensive to review manually. That connection is our interpretation of the two businesses. [7]
How the valuation reached 15 billion dollars
In January 2026, OpenEvidence announced a $250 million Series D round at a $12 billion valuation, co-led by Thrive Capital and DST Global. At that point, the company said it had raised roughly $700 million over the preceding 12 months. [4]
September's reported $15 billion valuation represents a 25% increase from January. That percentage is our calculation using the two reported valuations. [1][4]
The figures describe different things. The $250 million is the new investment. The $15 billion is the reported valuation attached to the financing. It does not represent annual sales or cash in the bank.
A funding valuation also measures investor expectations. It cannot establish how accurately a tool answers a clinical question or whether patients receive better care.
How a free product makes money
Advertising pays for OpenEvidence's free clinician access. The company's advertising policy says it accepts advertisements to cover the cost of providing the service. MedCity News reported that pharmaceutical companies buy ads on the platform. [8][9]
Nadler explained to MedCity News that the company displays an advertisement while the system gathers evidence and generates an answer. He said the advertisement disappears once the answer is ready. [9]
The commercial appeal is understandable. A drug manufacturer can reach a verified healthcare professional using a medical research tool. An advertiser may value that audience differently from someone casually browsing a general website.
OpenEvidence's policy says its answer-generation and advertising systems are separate. It also says advertisers cannot influence the information in answers and that the platform distinguishes advertisements from medical content. Those are the company's stated safeguards, rather than an independent audit of its systems. [8]
In its January funding announcement, OpenEvidence said it had reached $100 million in annual revenue. That gives readers a dated financial reference alongside the funding figures, although the company has not supplied current financial statements for this article. [4]
For this business model to keep working, clinicians need to find the tool useful enough to return. They also need confidence that commercial relationships do not determine the answers they receive.
Why investors value physician adoption
OpenEvidence allows clinicians to sign up directly. MedCity News described this approach as a way to reach doctors without first requiring a hospital to purchase and deploy the product. [9]
In September, Fierce Healthcare reported that OpenEvidence had 1.12 million verified U.S. clinicians using it, including physicians, nurses, nurse practitioners, and physician assistants. Nadler also told Fierce it was tracking more than 40 million verified clinician queries over a 30-day period. These are company-reported adoption figures. [10]
Our reading is that this helps explain the valuation. Free access removes the individual subscription decision, and a useful research tool gives clinicians a reason to return. Repeated use creates opportunities to earn advertising revenue.
Institutional partnerships can add another reason to use it. On September 16, OpenEvidence and Memorial Sloan Kettering Cancer Center announced a collaboration to integrate OncoKB, the cancer center's database for interpreting cancer-related genetic alterations. The announcement also described plans to integrate OpenEvidence into the center's Epic electronic health record workflow. [3]
The partnership adds curated information about which genetic findings may matter for treatment decisions. It illustrates how the product can develop beyond a general search interface. The announcement describes capabilities and intended benefits; it does not establish improved patient outcomes. [3]
What this means for your doctor
For an independent physician, the practical question is whether OpenEvidence helps answer a clinical question efficiently and reliably. For a patient, the question is how the physician checks and applies that answer.
This is part of the broader shift we covered in Abridge's expansion into clinical decision support. Research assistance also serves a different purpose from the documentation tools explained in our guide to AI scribes and visit recordings.
When comparing concierge medicine and direct primary care, ask how the physician uses research tools, reviews their sources, and explains treatment choices. Patients looking for care in New York or elsewhere can ask the same questions.
OpenEvidence's reported $15 billion valuation reflects a substantial investment in how doctors find and use medical information. Patients benefit when a physician combines useful research with an understanding of their history, preferences, and follow-up needs. The value of that work has to be demonstrated in care, beyond the funding announcement.
FAQ
What is OpenEvidence worth
September 2026 reporting places OpenEvidence's private funding valuation at $15 billion following a $250 million investment. Nadler confirmed the round and lead investors to Becker's Hospital Review. [1]
Is OpenEvidence free for doctors
Yes. The company says its core service is free for verified U.S. clinicians, with advertising helping cover its costs. [3][8]
Can advertisers influence OpenEvidence answers
OpenEvidence's advertising policy says advertisers cannot influence its answers and that its information and advertising systems operate separately. This describes the company's policy, not an independent verification. [8]
Does OpenEvidence replace a doctor
No. Its terms say the service provides educational and informational support for healthcare professionals and does not substitute for their clinical judgment. [2]
You can search NextMD for physician-led concierge and DPC practices, compare available pricing, and review doctor credentials.
Sources
Bruce, G. (2026, September 28). OpenEvidence raises $250M at $15B valuation. Becker's Hospital Review. Read the funding report.
OpenEvidence. (Accessed October 5, 2026). Terms of Use. Read OpenEvidence's terms.
OpenEvidence and Memorial Sloan Kettering Cancer Center. (2026, September 16). Memorial Sloan Kettering Cancer Center and OpenEvidence Partner to Advance Precision Oncology at the Point of Care. Read the partnership announcement.
OpenEvidence. (2026, January 21). OpenEvidence Raises $250 Million to Build Medical Superintelligence for Doctors. Business Wire, syndicated by FinancialContent. Read the company's January funding announcement.
OpenEvidence, Inc. (2025, June 20). Complaint in OpenEvidence, Inc. v. Doximity, Inc. et al., paragraph 34, PDF page 15. Read the company's founding account in its complaint.
Symposium on Artificial Intelligence for Learning Health Systems. (2025). Zachary Ziegler. Read the cofounder's speaker biography.
S&P Global. (2018, March 6). S&P Global to Acquire Kensho; Bolsters Core Capabilities in Artificial Intelligence, Natural Language Processing and Data Analytics. Read the acquisition announcement.
OpenEvidence. (Accessed October 5, 2026). Advertising Policy. Read the advertising and answer-separation policy.
Adams, K. (2026, February 8). Thunderstruck By OpenEvidence's $12B Valuation? Don't Be. MedCity News. Read the CEO and investor interviews about the business model.
Landi, H. (2026, September 22). OpenEvidence, Memorial Sloan Kettering Cancer Center partner to bring precision oncology AI to more doctors. Fierce Healthcare. Read the company-reported adoption figures and partnership coverage.