What Is an NPI Number?
An NPI (National Provider Identifier) is a unique 10-digit number assigned to every healthcare provider in the United States. Created under HIPAA in 2004 and mandatory since 2007, it serves as the standard identifier for healthcare transactions, billing, and administrative processes. You can look up any provider’s NPI for free on MedicareNPI.
Who Assigns NPI Numbers?
The Centers for Medicare & Medicaid Services (CMS) assigns NPI numbers through the National Plan and Provider Enumeration System (NPPES). Any healthcare provider who bills insurance or transmits health data electronically must apply for an NPI — it’s free and takes about 10 business days to receive.
Type 1 vs Type 2 NPI
There are two types of NPI numbers, each serving a different purpose:
Type 1 — Individual Providers
Assigned to individual healthcare professionals such as physicians, dentists, nurses, therapists, and pharmacists. A Type 1 NPI is tied to the person, not their employer or practice.
Type 2 — Organizations
Assigned to healthcare organizations such as hospitals, clinics, group practices, nursing facilities, and medical equipment suppliers. A provider who is also a sole proprietor may have both types.
Who Needs an NPI Number?
- Physicians (MDs and DOs)
- Dentists and oral surgeons
- Nurse practitioners and physician assistants
- Psychologists and licensed therapists
- Chiropractors and physical therapists
- Pharmacists and pharmacies
- Hospitals and medical clinics
- Home health agencies
- Medical equipment suppliers (DMEPOS)
Why NPI Numbers Matter for Patients
As a patient, knowing your doctor’s NPI number can help you:
- Verify that a provider is legitimately registered with CMS
- Confirm their specialty and credentials using tools like MedicareNPI
- Check Medicare enrollment status and MIPS quality scores
- File insurance claims or resolve billing disputes
- Research a provider on MedicareNPI before scheduling an appointment
Key Facts About NPI Numbers
- Format:Exactly 10 digits, starting with 1 or 2
- Cost:Free to obtain and maintain
- Permanence:Never expires — stays with the provider for life
- Portability:Does not change with location, employer, or specialty changes
- Registry:Over 7.5 million active NPI numbers in the US
Frequently Asked Questions
What does NPI stand for?
NPI stands for National Provider Identifier. It is a unique 10-digit number assigned to every healthcare provider in the United States by the Centers for Medicare & Medicaid Services (CMS).
Do all doctors have an NPI number?
Yes. Every healthcare provider who transmits health information electronically — including doctors, dentists, nurses, therapists, pharmacists, and hospitals — must have an NPI number under HIPAA regulations.
Does an NPI number expire?
No. Once assigned, an NPI number stays with the provider permanently. It does not expire and does not change even if the provider moves, changes specialties, or switches employers.
Is an NPI number the same as a medical license?
No. An NPI is a federal identification number used for billing and administrative purposes. A medical license is issued by a state licensing board and grants permission to practice medicine.
How can I look up an NPI number for free?
You can search any provider's NPI number for free on MedicareNPI.com, which combines NPPES registry data with CMS Medicare data including MIPS quality scores and telehealth availability. The official NPPES registry at npiregistry.cms.hhs.gov is another option.