What is an NPI (National Provider Identifier)?
A National Provider Identifier (NPI) is a unique 10-digit identification number assigned to healthcare providers by the Centers for Medicare & Medicaid Services (CMS), used on insurance claims, credentialing applications, and other healthcare transactions.
NPIs come in two types. A Type 1 NPI belongs to an individual clinician; a Type 2 NPI belongs to an organization such as a group practice or agency. Many ABA practices need both — one for the business and one for each clinician who has to be identified on claims.
The number is issued through the national registry CMS maintains and stays with the provider. It is not a credential or a license: holding an NPI says nothing about whether a provider is certified or in-network, only that they can be identified in standard healthcare transactions.
Claims use NPIs to identify the billing and rendering provider, and payers reference them throughout credentialing and enrollment, so keeping the registered information accurate avoids downstream claim problems.