The Moat

The Moat

Doximity's competitive advantage is really two advantages of different widths. Around the audience — more than 85% of U.S. physicians, using its workflow tools daily — the moat is wide and expensive to copy. Around the revenue — a slice of a discretionary, cyclical pharmaceutical marketing budget that Medscape and newer AI-native rivals also chase — it is narrower. The retention slide from 119% to 109% is where the second moat is visibly bending, which is why the slowdown is worth reading carefully rather than dismissing.

Source: FY2026 Annual Report (Form 10-K), MD&A — Overview and Key Business Metrics [1]; workflow-provider count [2].

The audience side: near-universal, and still widening

The starting point of any moat claim here is coverage. As of March 31, 2026, Doximity reported over 3 million registered members representing more than 85% of U.S. physicians across all 50 states and every specialty, plus about two-thirds of U.S. nurse practitioners and physician assistants [3]. Four years earlier the network already held more than 80% of physicians and over 90% of graduating medical students, on a base of two million members [4]. Reach that starts above 80% cannot compound the way a young network does; the durable edge is that it kept adding physicians while capturing the students who become the next cohort of prescribers.

Two structural features make the audience hard for a rival to reconstruct. First, membership is credential-verified: each profile functions as a validated digital curriculum vitae tied to training, licenses, affiliations and specialty, and members must be verified before they gain access to the network and productivity tools [5]. Verified identity is what lets a pharmaceutical customer trust that it is reaching a real, targetable prescriber rather than anonymous traffic. Second, Doximity is, on its own account, the only professional network dedicated solely to medical professionals — it competes for members against LinkedIn, Facebook, Google and X, none of which is purpose-built for clinical work [6]. The counter-fact a skeptic should hold: those platforms are vastly larger and better capitalized, and "purpose-built" is a positioning claim, not a legal barrier. What converts it into a barrier is not the network page but the workflow.

Engagement: used, not just registered

A membership roster is only an asset if physicians return to it. Here the evidence is unusually concrete, and it recently became more so. Doximity discloses that quarterly unique active providers using its workflow tools reached 0.81 million in FY2026, up from 0.62 million in FY2025 and 0.58 million in FY2024 [7]. On the earnings calls the same story is louder: a record 590,000 unique active prescribers used its generative-AI, telehealth, messaging and scheduling tools in a single quarter of FY2025, with daily active users growing the fastest of any cadence — the sign that the app has moved into day-to-day clinical routine rather than occasional reference [8].

Source: FY2026 Annual Report (Form 10-K), Key Business Metrics — figures presented in millions, shown here in thousands [9].

This metric deserves a caveat that also strengthens it. Doximity historically featured engagement figures on its calls without defining them in its filings; a March 2026 SEC comment letter pressed the company to define, quantify and analyze those metrics in MD&A, and Doximity agreed to do so beginning with the FY2026 10-K, drafting a figure of 634,000 quarterly workflow providers for March 2025 [10]. The now-published definition counts a provider who, in a quarter, places a call lasting more than ten seconds, sends a fax or secure message, submits a prompt to its clinical-AI tool, or uses its scheduling or ambient-notes tools [11]. The bar for "active" is therefore low, and the number is management's own until an auditor tests it — but the metric is now a defined, filed disclosure rather than a call talking point, and it spans EHR-integrated tools that a competitor cannot easily insert into a physician's existing workflow. Embedded scheduling, dialer and documentation tools are the switching cost: they raise the effort of leaving, which is what a verified-identity network alone does not.

Monetization: land-and-expand, and where it bends

The audience is monetized through expansion inside a concentrated set of large customers. Big pharmaceutical customers typically start with a handful of brands and then add modules and roll the platform across their portfolio once they see quantifiable returns; health systems follow the same path across service lines [12]. That mechanism shows up in the numbers: the count of customers spending at least $500,000 rose from 100 (FY2024) to 118 (FY2025) to 125 (FY2026), and that cohort alone accounted for roughly 83% of revenue in FY2026 [13]. How that expansion has moved quarter by quarter inside the largest accounts, and where it turned down, is taken up in The Upfront Shock.

Net revenue retention measures subscription revenue from the same customers year over year, capturing renewals, expansion, contraction and churn in one figure, and it is where the strain appears. It ran 114% in FY2024, rose to 119% in FY2025, then fell to 109% in FY2026 [14]. A reading of 109% still means the existing base grew — customers are not leaving in numbers — but the rate of net expansion has roughly halved from its peak. Because the company itself notes the metric is directly tied to its revenue growth rate, the retention slide and the growth slowdown are the same event measured two ways, not two separate warnings.

Source: FY2026 Annual Report (Form 10-K), Key Business Metrics — Net Revenue Retention Rate [15].

The competitive front

Doximity's own filing draws the competitive map by budget rather than by product. For marketing dollars it competes with established health-media outlets such as WebMD's Medscape and with newer entrants like OpenEvidence, an AI-native clinical-reference product [16]. The indexed pure-play peer, OptimizeRx, competes for the same pharmaceutical-advertiser spend but through a different channel — point-of-care messaging inside EHR and e-prescribing systems rather than an owned physician network [17]. That difference in model is the clearest evidence for the moat: on comparable latest fiscal years, Doximity earns roughly six times OptimizeRx's revenue at a net margin about six times as wide (30% versus 5%).

Sources: Doximity FY2026 revenue and net income per the FY2026 10-K MD&A [18]; OptimizeRx figures per its reported FY2025 financials [19].

The scale gap is real, but it is not the same as immunity. Two competitive facts cut against the moat. Medscape reaches physicians through content without needing to own their workflow, which shows that a marketing budget can be captured by a large audience Doximity does not control. And OpenEvidence's presence in the filing is the more important tell: an AI-native clinical-reference tool competes for exactly the physician attention and the "innovation" budgets Doximity is now targeting with its own clinical AI. A well-funded rival can copy a content channel or an AI reference tool far faster than it can rebuild a verified, workflow-embedded network — but it does not need to rebuild the network to take the advertising dollar.

Cyclical or structural

The retention slide has two readings, and management's own framing points to the cyclical one. On the Q4 FY2026 call, the company attributed soft demand to the HCP digital pharmaceutical-ad market broadly — elevated policy uncertainty and macro risk — and guided to overall market growth "at or below 5%," with brands making upfront commitments but on shorter planning horizons [20]. Three facts support reading the slowdown as demand-side rather than share loss: 65% of subscription-revenue guidance was booked at the start of the year, in line with the three-year average; engagement was described as at record levels; and revenue and engagement were each up more than 50% versus three years earlier [21]. A network losing its grip does not usually post record usage while its booking pace holds steady.

The structural reading is not thereby retired. If pharmaceutical marketing budgets are simply doing more with less, and if AI-native tools let advertisers reach physicians without paying for Doximity's owned audience, then a cyclical soft patch can harden into a lower plateau. The evidence in this chapter lands on a measured split. The moat around the audience — verified identity, near-universal reach, embedded daily workflow — reads as wide and durable; nothing here suggests physicians are leaving. The moat around the revenue is narrower: it is a share of a discretionary budget, and a 109% retention rate shows that share expanding more slowly than the network's engagement would imply. The split is most sensitive to whether Doximity's own clinical-AI products convert that record engagement back into expanding customer spend faster than AI-native rivals convert it into an alternative advertising channel, a question the AI monetization and recent-results chapters can weigh against the numbers.