The National Provider Identifier (NPI) is a unique, 10-digit numeric code assigned to covered healthcare providers in the United States. This standard identification number is used to identify a provider in administrative and financial transactions across the healthcare system. It acts as a consistent identifier for doctors, dentists, nurses, and other practitioners, regardless of the payer or location. The NPI is permanent and stays with the provider throughout their career.
The Function and Mandate of the NPI
The NPI was established to create a standardized system for identifying healthcare providers and streamline electronic administrative transactions. This standardization was mandated by the Health Insurance Portability and Accountability Act (HIPAA) of 1996 under its Administrative Simplification provisions. Before the NPI, providers used various proprietary identifiers issued by different health plans, causing complexity and inefficiency in billing and claims processing.
The NPI replaced older, non-standard identifiers, such as the Unique Physician Identification Number (UPIN). Requiring all covered entities to use the single NPI simplifies the electronic exchange of health information, including claims submissions and eligibility checks. This unified approach reduces administrative burden and costs for providers, health plans, and clearinghouses. Any provider engaging in HIPAA-covered electronic transactions must obtain and utilize this unique number, which is also required to enroll with Medicare or participate in other federally funded healthcare programs.
NPI Structure and Identifier Types
The NPI structure is “intelligence-free,” meaning the 10 digits do not contain coded information. The number does not embed details about the provider’s location, specialty, license number, or education. This random assignment prevents the need to issue a new number if a provider moves or changes their field of practice.
There are two distinct types of NPIs based on the entity applying for the number. A Type 1 NPI is assigned to individual healthcare providers, such as a doctor, physical therapist, or nurse practitioner who is a sole proprietor. An individual provider is eligible for only one Type 1 NPI, which is tied to them personally.
A Type 2 NPI is assigned to organizational healthcare providers, including hospitals, clinics, group practices, and incorporated medical groups. These organizations bill for services under their own business name and Tax Identification Number (TIN). An individual provider who is incorporated may hold both a Type 1 NPI for themselves and a Type 2 NPI for their corporation. This distinction allows for accurate tracking of both the individual who rendered the service and the organization that received the payment.
How the Public Uses and Verifies an NPI
For the general public, the NPI is a tool for verification. Patients may encounter the NPI printed on medical bills, insurance claim forms, or prescription labels. Knowing a provider’s NPI allows a patient to confirm that the person or entity providing care is a registered healthcare provider.
The public can use the National Plan and Provider Enumeration System (NPPES) Public Registry, a database maintained by the Centers for Medicare and Medicaid Services (CMS). This online resource allows users to search for a provider by name, location, or NPI. The registry provides publicly disclosable information, such as their practice location, phone number, and taxonomy code, which specifies their specialty. Using the NPPES database is the definitive way for a patient to verify the professional identity of a healthcare provider.