Healthcare Data GlossaryProvider
NPI Number: Definition and Healthcare Context
Full name: National Provider Identifier
The National Provider Identifier (NPI) is a unique, 10-digit numeric identifier assigned to health care providers in the United States under HIPAA Administrative Simplification. Administered by CMS through NPPES, an NPI is permanent and does not change when a provider changes their name, address, or taxonomy. All HIPAA-covered health care providers must obtain an NPI for use in administrative and financial transactions, including claims, eligibility inquiries, and remittance advice.
Last updated: 2026-05-31Reviewed by: Dr. Jennifer Montecillo, MD — Gullas College of Medicine, 2019. Non-practicing medical reviewer.
How it’s used
- CMS NPPES NPI Registry: every NPI in the public database links a provider's name, address, and taxonomy code to their unique 10-digit identifier.
- CMS PECOS Medicare Provider Enrollment: enrollment records cross-reference NPIs against Medicare billing rights and reassignment data.
- CMS Open Payments: physician payment disclosures are keyed to NPI, enabling financial-relationship lookups by individual provider.
- CMS QPP MIPS: clinician performance scores are published at the NPI level, making NPI the join key between payment data and quality scores.
Frequently asked questions
- What is an NPI number?
- An NPI (National Provider Identifier) is a unique 10-digit number assigned by CMS to every HIPAA-covered health care provider or organization in the United States.
- Who needs an NPI number?
- All HIPAA-covered health care providers — physicians, nurses, dentists, pharmacists, hospitals, group practices, and others — are required to obtain an NPI for use in electronic administrative transactions.
- Does an NPI number change?
- No. An NPI is permanent and does not change when a provider changes their name, address, specialty, or employer.
- What is the difference between a Type 1 and Type 2 NPI?
- A Type 1 NPI is assigned to individual providers (persons). A Type 2 NPI is assigned to organizations such as hospitals or group practices.