The difference is simple: a Type 1 NPI identifies an individual person, and a Type 2 NPI identifies an organization. A physician has a Type 1. The group practice that employs her has a Type 2. Both are 10-digit numbers from the same registry, and you cannot tell them apart by looking at the digits, only by looking the number up.
Why two types exist
A healthcare claim has to answer two different questions: who performed the care, and who should be paid for it. Those are often different parties. The rendering clinician is a person; the entity billing the payer is usually a practice, hospital, or company. Two identifier types let one claim carry both answers cleanly.
Who gets a Type 1
Every licensed clinician who bills electronically: physicians, NPs, PAs, dentists, therapists, pharmacists, and so on. One number per person, for life. It does not change when the provider changes employers, which is exactly why an NPI is such a reliable key for tracking a provider's history across jobs and states.
Who gets a Type 2
Organizations that deliver or bill for care: group practices, hospitals, health systems, pharmacies, labs, home health agencies, ambulatory surgery centers. Large organizations can enumerate subparts, so a hospital may hold several Type 2 numbers for different units or locations.
When one person holds both
Common case: a solo clinician who incorporates. Dr. Alvarez the person keeps her Type 1. Alvarez Dermatology PLLC, the legal entity that bills, gets its own Type 2. On her claims, her Type 1 appears as the rendering provider and the PLLC's Type 2 as the billing provider. An unincorporated sole proprietor, by contrast, operates under the Type 1 alone.
How claims actually use them
- Rendering provider: Type 1, the person who delivered the care.
- Billing provider: usually Type 2, the entity getting paid.
- Ordering or referring provider: Type 1, and for Medicare that person must be enrolled or validly opted out.
The most common billing mistakes are type confusions: submitting the group's Type 2 where the payer wants the individual rendering NPI, or assuming an organization's number somehow covers its clinicians. It does not. Each clinician bills under their own Type 1.
How to tell which type a number is
Look it up. The registry record labels every NPI as Individual or Organization, and NPivot's free lookup shows the type on every result, along with specialty, address, and enrollment dates. For a group, NPivot can also show the roster of clinicians who reassign to it, which is the org chart nobody publishes.
Check any provider right now. The free NPivot NPI lookup searches the registry by name or number, no login required. A free account adds Medicare enrollment, prescribing, procedure volumes, and revalidation dates on one page.