What is the difference between NPI Type 1 and NPI Type 2?

NPI Type 1 (also called individual NPI) is assigned to a single human healthcare provider — a physician, nurse practitioner, dentist, physical therapist, or any other licensed individual. NPI Type 2 (organizational NPI) is assigned to a group practice, hospital, lab, imaging center, or other healthcare organization. An individual physician working in a group practice has their own Type 1 NPI; the practice also has its own Type 2 NPI.

What Is an NPI Number and What Can You Look Up?

Q: What is an NPI number?

An NPI (National Provider Identifier) is a unique 10-digit number assigned by CMS to every licensed healthcare provider in the United States. It was created under HIPAA to serve as a universal provider identifier for billing Medicare, Medicaid, and most private insurance. Once assigned, an NPI does not change — it stays with the provider for life, even if they move or change specialties.

Q: Who is required to have an NPI?

Any 'covered health care provider' under HIPAA must have an NPI. This includes physicians, nurses, dentists, chiropractors, optometrists, physical therapists, psychologists, podiatrists, pharmacists, hospitals, labs, ambulances, and health plans. Providers who do not bill Medicare or Medicaid are not legally required to enroll, though many do so for industry interoperability reasons.

Q: What information can you look up with an NPI number?

The public NPI registry shows: the provider's name (or organization name), credential (MD/DO/NP/etc.), primary practice address, phone number, specialty taxonomy (NUCC code and description), entity type (individual or organization), and the date the record was last updated. It does not include email addresses, hospital affiliations beyond the provider's own filing, board certification status, or disciplinary history.

Q: How do I look up an NPI number for a specific doctor?

Go to npiregistry.cms.hhs.gov and search by the provider's first name, last name, and state. The registry returns all matching records. If you already know the NPI number, you can do an exact lookup by entering it in the NPI number field. The getdork Physician Search tool also queries the same registry, with the added ability to filter by zip code radius and specialty simultaneously.

By the getdork team — Published June 12, 2026

An NPI (National Provider Identifier) is a unique 10-digit number assigned by the Centers for Medicare & Medicaid Services (CMS) to every licensed healthcare provider in the United States. Once issued, the number is permanent — it never changes even if the provider moves, retires, or changes specialties. The NPI registry is public and free to search, and it gives you the provider's name, specialty, practice address, and phone number.

Why the NPI exists

Before NPIs, healthcare billing used a patchwork of identifiers — different numbers assigned by Medicare, Medicaid, and each private payer. HIPAA (the Health Insurance Portability and Accountability Act) mandated a single, universal provider ID to simplify billing and reduce fraud. CMS began assigning NPIs in 2006. By law, all covered healthcare providers who conduct electronic transactions with health plans must use their NPI.

The practical result: nearly every practicing licensed healthcare provider in the U.S. has an NPI on file, making the registry the most complete single source of licensed provider data the government maintains.

NPI Type 1 vs. NPI Type 2

The registry has two types of NPI records:

	Type 1 — Individual	Type 2 — Organization
Assigned to	A single human provider (physician, nurse, therapist, etc.)	A group, practice, hospital, lab, or other entity
Examples	Dr. Jane Smith, MD; John Doe, PT; Maria Garcia, NP	Memphis Heart Group; Regional Medical Center; Lab Corp
Name format in registry	First name + last name + credential	Organization name
Relationship	An individual may be affiliated with one or more Type 2 entities	An organization may employ many Type 1 providers
API filter	`entity_type_code=1`	`entity_type_code=2`

When you are building a prospect list of individual doctors, filter to entity_type_code=1. A cardiology group and the 12 cardiologists who work there all have separate NPI records — the group has a Type 2, each physician has a Type 1.

Who is required to have an NPI?

Under HIPAA, any "covered health care provider" must obtain an NPI. This includes:

Physicians (all specialties), including MDs, DOs, and osteopathic doctors
Nurse practitioners, physician assistants, certified nurse-midwives
Dentists and oral surgeons
Chiropractors, optometrists, podiatrists
Physical therapists, occupational therapists, speech-language pathologists
Psychologists, psychiatrists, licensed clinical social workers
Pharmacists and pharmacy technicians (in many states)
Hospitals, group practices, labs, imaging centers, ambulances

Providers who operate entirely outside Medicare/Medicaid billing are technically not required to enroll, but many do so to be recognized by private insurance networks. The coverage is effectively near-universal for practicing providers.

What you can look up with an NPI number

Data in every NPI record: NPI number, provider name (or org name), credential, primary practice address, phone number, specialty (NUCC taxonomy code + description), entity type, enumeration date (when the NPI was first assigned), and last-updated date.

The registry does not include:

Email addresses (not collected at enrollment)
Hospital or health system network affiliations (beyond the provider's own filing)
Board certification status (verify via the relevant specialty board's directory)
Disciplinary history or malpractice records (check state medical board databases)
Whether a provider is currently accepting new patients
Insurance plans accepted

How to look up an NPI number

Option 1: CMS web interface

The official registry is at npiregistry.cms.hhs.gov. Search by provider name and state to find a specific individual, or enter an NPI number directly for an exact lookup. No account required.

Option 2: CMS REST API

The free API at npiregistry.cms.hhs.gov/api/ lets you query programmatically. An exact NPI lookup looks like:

https://npiregistry.cms.hhs.gov/api/?version=2.1&number=1234567890

For a full guide to searching by specialty, city, zip, and radius, see How to search the NPI registry.

Option 3: getdork Physician Search

getdork queries the same CMS API and adds zip-code radius filtering, specialty dropdowns in plain English, and CSV export. Useful when you need a list of providers in a specialty within a geographic area rather than a single lookup.

Search by specialty and zip code radius — no API setup required.
getdork's Physician Search queries the NPI registry for you. Free to preview; Pro for the full result set and CSV export.

Start free at getdork.com →

NPI numbers in practice: sales and outreach use cases

The NPI registry is widely used by sales and research teams for legitimate outreach to licensed providers:

Medical device and pharmaceutical reps pull specialty-filtered lists by territory to plan call schedules and build CRM records. NPI + address + phone is enough to begin contact.
Healthcare staffing firms use Type 1 (individual) searches to find licensed providers in a specialty and market, then reach out about open positions.
Insurance credentialing teams use NPI lookups to verify a provider's identity and specialty taxonomy before adding them to a network panel.
Compliance and billing teams cross-reference NPIs in claims data to confirm provider identities and check that billing specialty matches on-file taxonomy.

Frequently asked questions

What is an NPI number?

An NPI is a unique, permanent 10-digit identifier assigned by CMS to every licensed healthcare provider in the U.S. It was created by HIPAA to standardize provider identification across Medicare, Medicaid, and private insurance billing. The number never changes once issued.

What is the difference between NPI Type 1 and Type 2?

Type 1 is for individual providers — a single physician, nurse, or therapist. Type 2 is for organizations — group practices, hospitals, labs. An individual doctor has a Type 1 NPI; their employer practice has a separate Type 2 NPI. Use entity_type_code=1 in the API to filter to individuals only.

Who is required to have an NPI?

Any HIPAA-covered healthcare provider who conducts electronic transactions with health plans must have an NPI. In practice, this covers virtually all physicians, nurses, therapists, dentists, chiropractors, and licensed healthcare organizations that participate in any insurance billing.

What information can you look up with an NPI number?

The public registry shows name, credential, practice address, phone, specialty taxonomy, entity type, and last-updated date. It does not include email, hospital network affiliations, board certification, disciplinary history, or whether the provider is accepting new patients.

How do I look up an NPI number for a specific doctor?

Go to npiregistry.cms.hhs.gov and search by name and state. For programmatic access, the free REST API takes a last_name + state query. getdork's Physician Search provides a simpler interface with specialty dropdowns and radius filtering.

Related guides

How to search the NPI registry (free guide) — detailed walkthrough of all search methods including API queries.
How to find cardiologists by zip code — a worked specialty search using the NPI registry.
How to find dermatologists by zip code — the same approach applied to dermatology.
How to find physical therapists by zip code — physical therapy provider search.