1 Dialer launch
Doximity Dialer launched in 2016 as a physician calling product.
Launch evidence for the caller-ID product context.
Case study
The identity infrastructure behind trusted telehealth
Built the identity infrastructure that let the office number travel with the physician on their personal phone — dissolving the bind between hospital desk phones and exposed personal numbers. The architecture decision was to make trust a product surface, not a compliance footnote.
Timeframe
2013–2017
Overview
The decision
Context 2
Physicians need to reach patients but face a structural bind: call from the hospital desk phone (geographically tethered) or from their personal cell (exposes their number permanently — no boundary, no audit trail, safety risk). Most choose neither, and the call doesn't happen. When they do call from a cell phone, patients see 'Unknown Caller' and don't answer.
Twilio required verifying ownership of a number before displaying it as caller ID — the legitimate path, but slower. A vendor offered to set any caller ID without verifying ownership; that route would never survive a hospital IT security review, and neither would the product itself — no security team green-lights physicians placing outbound calls under an office number from a personal phone.
The Decision 2
Proved it myself over a weekend — a working prototype placing outbound calls under an unverified caller ID — and launched on that vendor deliberately, inside a boundary worth stating precisely: the caller ID being set was the physician's own office number, used on their own device, at their own choice — an identity they already legitimately held, with no clinical decision-making in the loop.
What shipped ahead of institutional review was consumer adoption within the physician's own authority; what never shipped ahead of it was anything that could put a patient at clinical risk. Institutional authorization then came in the order institutions actually grant it: the move to verified telco attestation over spoofing, the HIPAA compliance policy, and the Epic Haiku integration gave hospital IT a documented basis to clear a product physicians were already using.
The sequence is where a principle I now design by was earned rather than contradicted — adoption may precede institutional approval only while the risk stays with the person choosing. When the risk is clinical, approval comes first.
Designed and shipped HIPAA-compliant verified caller ID and fallback workflows, making the clinician's office the visible, trusted identity on every outbound call. Two years earlier I had written Doximity's HIPAA policies, procedures, and white paper for the messaging products — the compliance posture Dialer then inherited rather than had to establish. Partnered with legal and hospital IT to clear EHR integration across multiple systems, including the Epic Haiku integration for one-tap verified calling inside the chart.
Outcome 3
Established the identity layer Dialer scaled on. 9 years after I left, Dialer was named the #1 Telehealth Video Conferencing Platform in the 2026 Best in KLAS Report — the fifth consecutive year — on ratings KLAS collects by interviewing health system leaders and their staff. Clinicians placed more than 300,000 calls through it on an average workday last quarter, and it carries virtual care and call shielding for more than 250 hospitals and health systems. The architecture held.
The paths considered
Twilio-verified caller ID Not chosen
The legitimate path — Twilio required verifying ownership of a number before displaying it as caller ID. Institutionally clean, but slower to ship.
Unverified vendor caller ID Chosen
A vendor offered to set any caller ID without verifying ownership. Faster to ship, but the route alone would never survive a hospital IT security review.
The caller ID being set was the physician's own office number, on their own device, at their own choice — an identity they already legitimately held, with no clinical decision-making in the loop. That kept the risk with the person choosing, which is what made shipping ahead of institutional review defensible. Verified telco attestation, the HIPAA compliance policy, and the Epic Haiku integration came after, in the order institutions actually grant authorization — giving hospital IT a documented basis to clear a product physicians were already using.
What survived contact
The assumptions the thesis rested on, and what testing it did to each.
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Physicians will call patients if the call can carry the office number Held
The launch cohort converted: of 904 physicians emailed, 36 placed a call within days, and daily volume went from roughly ten to nearly seven hundred in the first ten days. It now carries more than 300,000 calls on an average workday.
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An unverified caller ID is enough to build the product on Partly held
It proved the product over a weekend, but it could never survive a security review — verified telco attestation replaced it.
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Hospital IT will approve the product before physicians use it Did not hold
No security team pre-approves office numbers on personal phones. Consumer adoption inside the physician's own authority came first; the compliance policy then gave IT a documented basis to clear it.
Sources
2 Launch rationale, in my words
I stated the product's rationale on Doximity's blog at launch: "Easier communication leads to more communication, and greater communication leads to better health outcomes."
Dead at the original URL; cited to the Internet Archive snapshot. The title names the behavior the product replaced — physicians blocking caller ID with *67 and going unanswered.
3 Best in KLAS ranking
Dialer was named #1 Telehealth Video Conferencing Platform in the 2026 Best in KLAS Report, its fifth consecutive year, and carried more than 300,000 calls on an average workday last quarter across 250+ hospitals and health systems.
Replaces two 8-K citations that did not contain these figures — the filings themselves report revenue and AI-product usage, and the numbers had been attributed to earnings-call remarks that are not part of an 8-K.
KLAS derives its ratings from live interviews with health system leaders and their staff, so the earlier framing of "ranked by health system CIOs" was also wrong.
Claims previously made here and not supported by any source I can reach — a 3x pickup-rate advantage, ~45% of U.S. physicians on paid licenses, and beating Microsoft Teams and Zoom — have been removed rather than recited.
4 Telehealth provider volume
Over 300,000 unique active providers used Doximity telehealth tools in the quarter ended March 31, 2021.
Dated SEC filing, cited in place of undated company marketing copy. The filing's words: “We had over 300,000 unique active providers use our telehealth tools in the quarter ended March 31, 2021.” It defines a provider broadly — physicians, doctors of osteopathy, physician assistants, nurse practitioners, and medical students.
5 Epic Haiku integration
Dialer integrated with Epic Haiku.
Public integration evidence for clinical-workflow reach.
6 Epic Showroom listing
Dialer appears in Epic Showroom.
Public listing evidence for the product ecosystem.
Dialer's current scale is sourced to Doximity's SEC filings below. The launch figures come from my own launch review; the weekend prototype and the Epic Haiku integration are my account and have no external record. The iOS rating covers the whole app portfolio I ran, not Dialer alone.
End-to-end flow
1 Doctor opens Dialer → 2 Enters patient phone number → 3 System sets office number as caller ID → 4 Patient sees 'Dr. Smith's Office' on phone → 5 Patient answers → 6 Call connected with office identity
Implementation
Constraints
- Physicians can't share personal phone numbers with patients — boundary, safety, liability, and no audit trail. The office number had to serve as the trust proxy.
- Hospital desk phones tether physicians to a physical location. The product had to liberate the office number without exposing the personal number.
- Hospital IT security reviews would never pre-approve a product that lets physicians use office numbers from personal devices — consumer adoption, inside the physician's own authority, had to precede enterprise approval.
What was shipped
- Office number as caller ID via vendor integration, with fallback paths for carrier rejection.
- Audit-ready call logs and identity verification records.
- Epic Haiku integration putting calling inside the clinical workflow.
Outcomes 34
- The iOS rating rose from 3.7 to 4.8 stars over the same period, across the whole app portfolio.
Deliverables
- Caller ID mapping From the August 2016 MVP spec, when the product was still called CallPatient. Office, back office, and mobile as selectable identities — plus Ghost, an ephemeral number good for 24 hours, for the case where no owned number fits. The numbers shown were placeholders and have been removed.
- The decision to defer phone verification The same spec, four SMS-verification screens struck through: identity was already established by the Doximity account behind the app, so verifying the handset again was cost without protection. That shortcut is the assumption below that only partly held.
- Identity verification methods Four ways to prove you were a clinician, from the annotated iOS spec: a medical email domain, a DEA number, a photograph of a license, or a fax. Note the promise attached to the DEA field — used to verify, never stored. Doximity's own fax number has been removed.
- HIPAA policies, procedures, and white paper Written in 2014 for the messaging products — the compliance posture Dialer inherited two years later. Doximity's document, so described here rather than republished.
Artifacts
Why it matters
When the call connects, a lab result gets communicated tonight instead of next week. A post-discharge follow-up reaches the patient before a complication sends them back to the ER. A physician who gets a biopsy result at 7pm can call from home — the patient sees the office number and answers, the personal boundary stays intact, and the diagnosis doesn't wait until morning.
The first sign it was working wasn't a metric: medical residents I'd gone to undergrad with told me they were getting more sleep at night — they could call patients from home with the office number instead of staying at the hospital to use the desk phone.
At Transcarent, the problem changed from trust to scale: how to make that same trust work across four clinical programs at once.