NPPES and the NPI Registry, explained
NPPES (the National Plan and Provider Enumeration System) is the system the Centers for Medicare & Medicaid Services (CMS) uses to assign every US healthcare provider a unique 10-digit National Provider Identifier (NPI). The public part of NPPES is the NPI Registry: a searchable record of each provider's NPI, name, specialty, and practice location. NPIRadar republishes that same public data as a browsable directory.
What is in the NPPES NPI Registry?
Every NPI record is one of two entity types:
- Type 1 — individuals: physicians, dentists, nurses, therapists, pharmacists, and other individual practitioners, including sole proprietors.
- Type 2 — organizations: hospitals, clinics, group practices, pharmacies, labs, home health agencies, and suppliers.
For each NPI, the public registry shows:
- Provider or organization name, and credentials for individuals
- Taxonomy code(s): the NUCC classification that serves as the provider's specialty
- Practice location and mailing address, with phone number
- State license number(s) tied to each taxonomy
- Enumeration date, last-updated date, and deactivation status
An NPI is “intelligence-free”: the number encodes nothing about the provider except a final check digit, which you can test with the NPI validator. It stays the same for life, even when the provider moves or changes specialty.
Who has to have an NPI?
HIPAA requires an NPI for any healthcare provider that bills electronically. The NPI replaced the older payer-specific identifiers (UPIN, Medicaid and commercial plan numbers) on claims, and it now appears on insurance claims, prescriptions, and referrals. Getting one is free: providers apply online through NPPES. Providers are also expected to update their NPPES record within 30 days of a change, such as a new practice address.
How NPPES data is published
CMS releases the public NPPES data three ways:
- The NPI Registry website: a search form on CMS's site, for one provider at a time.
- The NPI Registry API: a free JSON API from CMS. Each request returns a capped page of results, so it works for lookups but not for pulling a whole specialty or city.
- The NPPES Downloadable File: a full monthly replacement file of every record (several GB of CSV), with weekly incremental updates. It's complete, but you need a database to use it.
How to search the NPI Registry on NPIRadar
NPIRadar loads the NPPES Downloadable File (currently the NPPES — May 2026 release) into a database and indexes it the ways people actually search:
- By NPI number or name: the NPI lookup on the home page.
- By specialty, then city: the specialty directory lists every NUCC taxonomy with its provider count.
- Many NPIs at once: bulk NPI lookup takes up to 100 numbers per batch, with CSV export.
- From code: the free NPI API offers single, bulk (100 per request), and filtered search, as JSON with no key.
NPIRadar is an independent directory. It is not affiliated with or endorsed by CMS. For an official record, or to update your own NPI data, use NPPES directly.