What is an NPI number?
An NPI (National Provider Identifier) is a unique 10-digit number that identifies a U.S. health care provider in standard administrative and financial transactions. It is assigned by CMS through the NPPES system, is free, never expires, and carries no information about the provider’s specialty, location or license.
What does an NPI look like?
An NPI is 10 digits, for example 1234567893. The first nine digits are an identifier and the tenth is a check digit calculated with the Luhn formula, which catches typing mistakes. Use the NPI validator to test one.
Who needs an NPI?
HIPAA covered health care providers must have an NPI and use it in standard transactions, such as claims, eligibility checks and referrals. Health plans and clearinghouses must accept NPIs in those transactions. Individual clinicians and organizations such as clinics, group practices and hospitals can all be enumerated.
What an NPI is not
- It is not a license. A state board issues licenses.
- It is not a credential or proof of good standing.
- It does not encode the provider’s specialty or location, which is why registry entries carry separate taxonomy and address fields.
How do I find someone’s NPI?
Search the registry on the NPI lookup page by name, organization, city and state. If you already have a number, search it directly to see the registry entry. The guide to looking up an NPI by name explains the search rules.
How does a provider keep the entry current?
Providers are responsible for keeping their NPPES record accurate. CMS requires covered providers to report changes to their NPPES information within 30 days.
Frequently asked questions
Can a provider have more than one NPI?
No. An individual has a single NPI for life, regardless of employer, location or specialty changes. Organizations may have additional NPIs for distinct subparts.
Does an NPI expire?
No. The number stays with the provider. The registry entry can be deactivated, for example when a provider retires.
Is the NPI registry public?
Yes. NPPES publishes provider information, and this site displays it as published.
Related guides
- How to look up an NPI by name: Find a provider’s NPI with a name, state or specialty.
- NPI types and taxonomy codes: Individual vs organization NPIs, and what a taxonomy code means.
Sources: CMS: National Provider Identifier Standard; CMS NPPES NPI Registry; NUCC Health Care Provider Taxonomy. This guide is general information, not legal or billing advice.