Physician email lists: free sources and bought lists

Individual clinicians and health care organisations are registered under a National Provider Identifier (NPI). CMS publishes the NPI data in two ways, both free: the NPI Registry, a query-only search updated daily, and a downloadable file replaced in full every month with weekly updates.

The November 2026 full file, dated 9 November, is a 1,079 MB zip of comma-separated data, too large to open in Excel. CMS says providers with active NPIs can't opt out of the published record.

What it gives you for free

For a postal or phone list of physicians, that is most of the work done. Filter by taxonomy (the specialty code) and state, and you have names, practice addresses and phone numbers without buying anything.

We queried the NPI Registry's public API on 9 November 2026 and read what each record returns, then compared it with what commercial physician lists are sold on.

• Ask how the addresses were found: guessed from name patterns, collected from public pages, or opted in. Guessed addresses bounce.
• Ask for the bounce rate the seller will stand behind and a sample you can verify.
• Ask whether you can match the list to NPI numbers; a seller who can is easier to check and to update.
• Consider a data append instead: send your own NPI-based file and pay only for the emails added.
• Check the licence: single use or multi-use, how long, and whether it covers email at all.

CAN-SPAM makes no exception for business-to-business email, so a message to a doctor's work address is covered like any other. It needs honest headers and subject lines, an ad disclosure, a valid postal address and an opt-out honoured within 10 business days, and each violating email can cost up to $53,088.

Using a sender doesn't move the responsibility. Health privacy law is a separate question: published provider directory data is about the provider, not patients, but any campaign that touches patient information needs advice first.