OpenEvidence, the pioneering AI platform meticulously designed for medical professionals, announced a groundbreaking development on Wednesday, revealing it has successfully secured $250 million in a Series D funding round. This substantial investment has propelled the Miami-based startup’s valuation to an astonishing $12 billion, marking a doubling of its previous valuation in a remarkably short period. The announcement underscores not only the burgeoning investor confidence in specialized AI solutions within healthcare but also OpenEvidence’s rapid ascent as a critical tool for clinicians worldwide.

This latest capital injection is particularly noteworthy given its timing and magnitude. It represents the fourth fundraise for OpenEvidence in less than a year, illustrating an aggressive and highly successful growth trajectory. Since its inception in 2021, the company has amassed nearly $700 million in total funding, a testament to its innovative approach and market traction. Previously, OpenEvidence was valued at $6 billion during its Series C funding round, which closed in October, highlighting a staggering increase in valuation within mere months. The Series D round was co-led by two prominent venture capital firms, Thrive Capital and DST, whose participation signals strong endorsement from seasoned investors known for backing transformative technologies. Further bolstering the investor syndicate are other heavyweights in the venture capital world, including GV (Google Ventures), Sequoia Capital, Kleiner Perkins, and Coatue, collectively affirming the immense potential seen in OpenEvidence’s mission and technology.

At its core, OpenEvidence describes itself as a specialized AI-powered medical search engine, but its function transcends a simple search tool. It positions itself as a "brain extender" for clinicians, a sophisticated co-pilot that navigates the vast and ever-expanding ocean of medical literature to provide immediate, citation-linked answers. This capability is paramount in modern medicine, where the sheer volume of new research, clinical trials, and updated guidelines makes it virtually impossible for individual doctors to stay abreast of every relevant development. By providing precise, evidence-based information directly linked to its sources, OpenEvidence empowers doctors to make more informed decisions, enhancing diagnostic accuracy, optimizing treatment plans, and ultimately improving patient outcomes. The platform’s commitment to being free for doctors and ad-supported underscores its mission to maximize accessibility, ensuring that critical medical intelligence is available to those on the front lines of patient care without financial barriers. This model allows for broad adoption, though it also necessitates a thoughtful approach to ad integration to maintain trust and neutrality within a clinical context. The company’s achievement of $100 million in annual revenue by January further validates the viability and success of this model.

The current landscape of artificial intelligence makes OpenEvidence’s rise particularly pertinent. Major generalist AI companies, such as OpenAI and Anthropic, are increasingly venturing into healthcare applications with offerings like "ChatGPT for Health" and "Claude for Health." While these general-purpose models demonstrate impressive capabilities, OpenEvidence distinguishes itself through its hyper-specialization. Its AI is not merely trained on general text but on a curated and constantly updated corpus of medical literature, clinical guidelines, and peer-reviewed research. This focused approach is critical for accuracy and reliability in a field where precision can mean the difference between life and death. The "citation-linked answers" feature is a crucial differentiator, offering transparency and verifiability that general AI models often lack, which is essential for building trust among medical professionals and meeting the rigorous demands of clinical practice.

The rapid adoption metrics shared by OpenEvidence paint a compelling picture of its impact. In December, the platform supported approximately 18 million clinical consultations from verified physicians across the U.S., a staggering increase from about 3 million consultations per month just a year prior. This exponential growth highlights a profound and urgent need within the medical community for such a tool. Furthermore, OpenEvidence proudly claims that its platform is utilized on a daily basis, on average, by more than 40% of all physicians in the U.S., spanning over 10,000 hospitals and medical centers. Such pervasive integration into daily clinical workflows signifies a paradigm shift in how doctors access and apply medical knowledge. The company’s assertion that more than 100 million Americans were treated by a doctor using OpenEvidence last year further underscores its broad societal impact, suggesting that its technology is already playing a significant role in public health outcomes across the nation.

Daniel Nadler, CEO and co-founder of OpenEvidence, who established the company with Zachary Ziegler, articulates the core problem OpenEvidence solves with striking clarity. "If a doctor tried to stay current by reading only the new evidence in the top 10 medical journals and only the most recent changes to their specialty guidelines, it would take nine hours of their day, each day," Nadler explained in a recent release. "Without a technology like OpenEvidence, doctors may miss critical new findings or guidelines simply because they lack the time to find them." This statement encapsulates the immense challenge of information overload faced by healthcare professionals and positions OpenEvidence not as a replacement for human intellect, but as an indispensable augmentation, a true "brain extender" that mitigates the risk of overlooking crucial, potentially life-saving information. Nadler and Ziegler’s vision for an AI-powered solution stems from a deep understanding of the practical realities and cognitive burdens placed upon medical practitioners.

The burgeoning interest in AI-related healthcare is not isolated to OpenEvidence; it represents a global trend. Crunchbase data indicates a significant surge in funding for this sector. Investors poured an estimated $14 billion into seed- through growth-stage funding for companies in AI-powered health tech categories in 2025 alone. This figure marks a substantial 63% increase over the $8.6 billion raised in all of 2024. This dramatic rise in investment underscores a growing recognition that AI has the potential to revolutionize various facets of the healthcare system, from diagnostics and personalized medicine to drug discovery and operational efficiencies. Startups like OpenEvidence are increasingly tackling "high-pain and high-cost parts of the healthcare system," offering scalable solutions to deeply entrenched problems. The influx of capital reflects a collective belief that AI can not only enhance the quality of care but also reduce costs and improve accessibility, making healthcare more effective and equitable.

With this significant Series D funding, OpenEvidence is poised for further expansion and innovation. The capital will likely be deployed to scale its platform, deepen its AI capabilities, broaden its reach to more medical specialties and potentially international markets, and invest in research and development to introduce new features. As the competitive landscape in AI healthcare intensifies, OpenEvidence’s early lead, strong investor backing, and proven adoption rates position it as a formidable player. Its specialized focus on delivering verifiable, citation-linked answers directly addresses a critical need for trust and accuracy in clinical settings, setting a high bar for competitors. The company’s trajectory suggests a future where AI is not just an ancillary tool but an integrated, indispensable component of medical practice, fundamentally transforming how doctors acquire knowledge and, in turn, how patients receive care. The journey of OpenEvidence from a 2021 inception to a $12 billion valuation in just a few years is a powerful narrative of how focused innovation, combined with a clear understanding of market needs, can rapidly reshape an entire industry, promising a more informed and efficient future for medicine.