Can You Look Up an NPI by Tax ID (EIN or TIN)?
Not directly. No public database links a tax ID to an NPI, but there are good workarounds, and for tax-exempt organizations our EIN tool gets close.
Why there's no tax ID search
The NPI registry has a field for an organization's EIN, but CMS withholds it. In the public NPPES data file the EIN column is blank or marked <UNAVAIL> for every record, and the registry search offers no tax ID option. Individuals often use their Social Security number as a tax ID, which is one reason it stays private. Providers' self-reported identifiers are free text: only about 9,000 of 9.4 million active NPIs mention anything that looks like a tax ID, so there is nothing reliable to search.
If it's a tax-exempt organization
Nonprofit hospitals, health centers and clinics file with the IRS, and the IRS publishes the EIN, name and address of every tax-exempt organization. Our EIN tool looks the EIN up there, then finds NPI records with the same name and address. The match is by name and address, not by a recorded link, so confirm it.
Methods that work for any provider
- Check a claim or remittance. A CMS-1500 shows the Federal Tax ID in item 25 and the billing provider's NPI in item 33a. Electronic remittances (835) carry both for the payee as well.
- Ask the provider's billing office. They know the NPI their tax ID bills under, and may have several.
- Use a payer portal. Many health plans' provider tools can show which NPIs are on file for a tax ID, if you're a contracted provider or authorized user.
- Look at the organization's record by name. Search the registry by name and compare city, state and specialty.
- Credentialing systems. Services such as CAQH hold the tax ID and NPI together, but access is limited to the provider and authorized plans.
Be careful with "NPI by TIN" services
Some data brokers sell tax ID to NPI matches. Their sources are unclear and the matches can be wrong. Don't use one for billing or payments without confirming with the provider. And never enter a Social Security number into a lookup tool.
Sources
Reviewed October 2026. Federal rules and CMS pages change; check them for the latest.
Look one up
Need a number now? Search the registry by NPI, name or organization.