TL;DR — Every Medicare provider needs an NPI before enrollment can start. A Type 1 NPI identifies an individual provider; a Type 2 NPI identifies an organization — group practices usually need both. NPIs are assigned through NPPES and are permanent, and the taxonomy code on your NPPES record must match the specialty you enroll under in PECOS, or your enrollment will be rejected. The National Provider Identifier (NPI) is a 10-digit number assigned to healthcare providers by CMS. It’s the universal identification number for healthcare providers in the US — used for Medicare enrollment, claims processing, and provider identification across all payers.
Every Medicare provider must have an NPI before they can enroll. And the type of NPI matters: the wrong NPI type, or an NPI with incorrect information, causes Medicare enrollment to fail.
What the NPI is (and isn’t)
What it is:
- A permanent, unique identifier for a healthcare provider
- Required for all HIPAA-covered transactions
- The identifier used in Medicare enrollment and claims
- Assigned by CMS through the NPPES (National Plan and Provider Enumeration System)
What it isn’t:
- A billing number (that’s a PTAN, assigned after enrollment)
- A license number
- A DEA number
- A Medicaid number
- Tax identification number
You need an NPI before you can enroll in Medicare. You’ll receive a PTAN (Provider Transaction Access Number) after your Medicare enrollment is approved.
Type 1 NPI: Individual providers
A Type 1 NPI is assigned to individual human healthcare providers. Every individual practitioner who provides healthcare services should have exactly one Type 1 NPI — it stays with them for life, regardless of where they practice.
Who gets a Type 1 NPI:
- Physicians (MDs, DOs)
- Nurse practitioners
- Physician assistants
- Physical therapists
- Occupational therapists
- Speech-language pathologists
- Clinical psychologists
- Licensed clinical social workers
- Any individual provider who delivers healthcare services
Key characteristics:
- One per person — you don’t get a new NPI when you change employers, move states, or change specialties
- Permanent — not reassigned even if inactive
- Associated with the individual’s legal name and personal information
- Requires update in NPPES when information changes
Type 2 NPI: Organizations
A Type 2 NPI is assigned to organizations — entities that provide healthcare services through their employees or contracted providers.
Who gets a Type 2 NPI:
- Group practices and clinics
- Hospitals and institutional providers
- Home health agencies
- DMEPOS suppliers
- Nursing facilities
- Any healthcare organization that submits claims
Key characteristics:
- Assigned to the organization, not individuals within it
- Associated with the organization’s legal name, EIN, and business address
- Different Type 2 NPIs for different locations/entities within a health system
- Requires update when organization information changes
Do you need both?
Individual in solo practice billing under their own name: Type 1 NPI only. You bill under your individual NPI.
Individual employed by or contracting with a group practice: Both. You need your Type 1 NPI for your individual Medicare enrollment (CMS-855I), and the group needs a Type 2 NPI for its organization enrollment (CMS-855B). You bill through the group’s Type 2 NPI.
Organization with multiple individual providers: The organization needs one Type 2 NPI. Each individual provider within the organization needs their own Type 1 NPI.
Multi-location group: Typically one Type 2 NPI for the organization, but there are scenarios where different legal entities within a multi-location group have separate Type 2 NPIs. This depends on the legal structure.
NPI and taxonomy codes
Every NPI in NPPES must have at least one taxonomy code — a standardized code that identifies the provider’s type and specialty. Your taxonomy code affects:
- Which Medicare enrollment pathway applies to you
- Which claim types Medicare will accept under your NPI
- How patients and payers find and identify you
The taxonomy code in your NPPES record must match the specialty you enroll under in PECOS. A mismatch causes enrollment rejection.
[Full taxonomy code guidance is on the relevant provider type pages — see the provider hub for your specialty.]
Keeping NPI information current
NPPES is the master record for your NPI. Changes to your:
- Legal name
- Primary practice address
- Contact information
- Taxonomy code(s)
…must be made in NPPES, which then flows to PECOS and other CMS systems. Don’t try to update NPI information through PECOS directly — update NPPES first.
⚠️ NPPES changes take 24–72 hours to propagate to PECOS and other CMS systems. Don’t file a Medicare enrollment update immediately after changing NPPES — wait at least 24 hours.
Finding your NPI
If you already have an NPI and can’t find it:
- Search the public NPPES NPI Registry at npiregistry.cms.hhs.gov — search by name, organization, or state
- Call your MAC
- Check your EOB (Explanation of Benefits) if you’ve previously received Medicare payments — your NPI should appear there
If you don’t have an NPI yet: Register at NPPES →
Related pages
- Type 1 NPI — Individual Provider Registration
- Type 2 NPI — Organization & Group Practice
- NPPES Registration Walkthrough
- NPI for Group Practices
NPI questions specific to your situation? Ask Mae →