Guide
What is an NPI number?
The National Provider Identifier explained: what the 10 digits mean, who must have one, how Type 1 and Type 2 differ, how to apply, and how to look up any provider in the NPPES registry.
Updated November 2026 · 9 min read · Sources: CMS, NPPES, NUCC
What an NPI is
A National Provider Identifier (NPI) is a unique 10-digit number assigned to health care providers in the United States. It is issued by the Centers for Medicare & Medicaid Services (CMS) through the National Plan and Provider Enumeration System (NPPES), and it identifies a provider in all HIPAA standard electronic transactions, such as claims, eligibility checks and referrals.
The NPI was created under the Health Insurance Portability and Accountability Act of 1996 (HIPAA). Before it existed, each health plan assigned its own provider numbers, so a single physician could carry dozens of identifiers. The NPI replaced them with one number that stays with the provider for life, regardless of job changes, relocation or specialty.
Who needs an NPI
Every health care provider that is a covered entity under HIPAA must obtain an NPI. In practice that means anyone who transmits health information electronically in connection with a standard transaction, including:
- Physicians, dentists, nurses, nurse practitioners, physician assistants and pharmacists
- Therapists, psychologists, counselors and clinical social workers
- Chiropractors, optometrists, podiatrists and audiologists
- Hospitals, clinics, group practices, nursing facilities and home health agencies
- Pharmacies, laboratories, ambulance companies and durable medical equipment suppliers
Providers who never bill insurance electronically are not legally required to have one, but most obtain an NPI anyway because health plans, e-prescribing systems and credentialing bodies ask for it.
Type 1 vs Type 2 NPI
NPPES issues two entity types. The number itself looks the same; the difference is who it identifies.
| Type 1 · Individual | Type 2 · Organization | |
|---|---|---|
| Who gets it | A single human provider: physician, nurse, therapist, pharmacist, etc. | A business entity: hospital, group practice, clinic, pharmacy, lab, agency |
| How many | Exactly one per person, for life | One or more; large systems often enumerate each location or subpart |
| Sole proprietors | Get a Type 1 only. A sole proprietorship is not a separate legal entity | Not applicable |
| On a claim | Rendering provider | Billing provider |
A physician who owns an incorporated practice typically has both: a Type 1 NPI for themselves and a Type 2 NPI for the corporation that bills. Browse individual providers or organizations in the directory.
Anatomy of the 10 digits
An NPI is always 10 numeric digits. The first digit is currently 1 or 2 (NPPES reserves other leading digits for future use). The last digit is a check digit calculated with the Luhn algorithm, the same formula used for credit card numbers, after prefixing the number with the constant 80840. This lets software catch most typos before a claim is submitted.
Nothing else is encoded. The entity type, state, specialty and license are stored in the NPPES record, not in the number.
Where the NPI is used
- Claims and billing. Required on every electronic claim (837), remittance (835) and eligibility inquiry (270/271) as the rendering, billing, referring or attending provider identifier.
- Prescriptions. Electronic prescriptions and pharmacy claims identify the prescriber by NPI.
- Credentialing and enrollment. Medicare, Medicaid and commercial plans key their provider files to the NPI.
- Referrals and orders. Ordering and referring providers must be identified by NPI for the service to be paid.
- Public records. Open Payments, Medicare utilization data and quality programs publish results by NPI.
NPI vs other identifiers
| Identifier | Issued by | What it identifies | Public? |
|---|---|---|---|
| NPI | CMS (NPPES) | A provider in HIPAA transactions | Yes |
| Taxonomy code | NUCC | Provider type and specialty (10 characters ending in X) | Yes |
| State license number | State licensing board | Legal authority to practice in one state | Yes, via the board |
| DEA number | Drug Enforcement Administration | Authority to prescribe controlled substances | No |
| Tax ID (TIN/EIN) | IRS | The entity paid for services | No |
| Medicare PTAN | Medicare Administrative Contractor | Enrollment in Medicare | No |
The NPI replaced the older UPIN and plan-specific legacy identifiers for transactions, but it did not replace licenses, DEA numbers or tax IDs, which serve different legal purposes. See the full list of taxonomy codes.
How to get an NPI
Applying is free and is done through NPPES. There are three routes:
- 1Online at NPPESCreate an Identity & Access (I&A) account at nppes.cms.hhs.gov, complete the application and receive the NPI, usually within 10 business days.
- 2Paper form CMS-10114Mail the form to the NPI Enumerator. Processing takes about 20 business days.
- 3Electronic File Interchange (EFI)Organizations can submit bulk applications on behalf of many providers.
You will need your legal name, date of birth, Social Security number (for Type 1), practice and mailing addresses, state license information and at least one taxonomy code.
How to look up an NPI
Because NPPES data is public, any NPI can be verified in seconds. On NPIFinder, type the 10-digit number, the provider’s name, or a specialty and city into the search box. Each profile shows the entity type, credentials, primary and secondary taxonomies, license numbers, practice and mailing addresses, phone and fax, enumeration date and last update.
Common reasons to look up an NPI include completing a claim or referral, verifying a prescriber before dispensing, credentialing a new hire, and confirming a provider’s specialty or practice location.
Try it with a real record
Dr. Nate D Quilici, MD · Portland, OR
Keeping a record current
Providers must report changes to their NPPES record within 30 days. The most common updates are a new practice address, a changed name, an added taxonomy, or a new state license. Updates are made in NPPES with the same I&A login used to apply.
An NPI can be deactivated when a provider dies, retires, or an organization dissolves. Deactivated numbers are never reassigned, and NPIFinder marks them as deactivated on the profile.
Frequently asked questions
Is an NPI number confidential?
No. The NPI and most of the NPPES record are public under the Freedom of Information Act. Social Security numbers, dates of birth and contact-person details are never disclosed.
Does an NPI expire or need renewal?
No. An NPI is issued once and never expires. It stays with the provider through job changes, relocations and specialty changes.
Can a provider have more than one NPI?
An individual may have only one Type 1 NPI. An organization may obtain several Type 2 NPIs for different locations or subparts.
How much does an NPI cost?
Nothing. Applying through NPPES is free. Third parties may charge to complete the application on your behalf, but the number itself is always free.
What is the difference between an NPI and a taxonomy code?
The NPI identifies who the provider is; the taxonomy code describes what kind of provider they are. A provider has one NPI but may list several taxonomy codes.
How quickly is NPIFinder updated when NPPES changes?
NPIFinder pulls records from the live NPPES NPI Registry API, so new and updated records appear as the index is refreshed. Each profile shows its NPPES last update date.