NPI vs tax ID (EIN): what is the difference?

Answer: The NPI identifies a health care provider on claims and prescriptions; CMS issues it. The EIN (Employer Identification Number) identifies a business for taxes; the IRS issues it. A solo provider can bill with a Type 1 NPI and their Social Security number, or get an EIN to keep the SSN off claims. Neither replaces the other.

What each number does

The NPI tells a payer who provided the care. The tax ID tells the payer whom to pay and report income for. Every claim carries both: the rendering provider's NPI and the billing entity's tax ID (an EIN or, for an unincorporated individual, a Social Security number).

Do you need an EIN to get an NPI?

No. An individual (Type 1) NPI is tied to your Social Security number. Many solo providers get an EIN anyway so their SSN does not appear on every claim and W-9; it is free from the IRS and takes minutes. A Type 2 NPI, by contrast, requires an EIN because it belongs to an organization.

Related identifiers

CAQH ProView ID (credentialing profile), PECOS enrollment (Medicare), DEA registration (controlled substances) and your state license number are all separate from the NPI. See NPI vs CAQH vs PECOS.

Need an NPI?

Option 1 · Free · Easiest

SimpleNPI files it for you

One short form: name, license, contact, address, identity and an e-signed authorization. About 3 minutes, no CMS account to create.
A person checks your license and address, then files the application with CMS under your signed authorization.
Your NPI arrives by email and text, with all the documentation, usually within 10 minutes. Filed after midnight Eastern? It issues around 6 am Eastern.

Usually within 10 minutes after the form is complete.

Start the free application

Option 2 · Free

Apply yourself at NPPES

Create an Identity & Access account at nppes.cms.hhs.gov.
Choose Apply for an NPI for myself, Individual (Type 1).
Enter identity, addresses, taxonomy code and license number, then certify and submit.

Usually a few business days; often minutes when the Social Security match passes.

Go to NPPES

Written by Ammon Hardin, LMT, who grew a massage practice to ten locations, built a veteran therapy network, and credentialed a large number of providers along the way. Updated Tue Oct 27, 2026. Free to read, free to use; SimpleNPI files NPI applications for free.