Plain-language guides to the public Medicare enrollment and provider data this tool checks — with a live, evidence-backed lookup behind every one. See also data sources & methodology.
The difference between a Type 1 (individual) and Type 2 (organization) NPI, why a provider can have both, and how entity type changes which Medicare checks apply.
An NPI proves a provider exists in the national registry — not that they take Medicare. What the registry does and does not say, and which Medicare signals you can actually check.
Three layers of NPI verification: format validity via the check digit, live registry status from NPPES, and identity match. How to run all three on any 10-digit number, free.
How to find a provider's NPI when you only have a name: search the registry, disambiguate common names by state and specialty, and confirm you have the right record.
A quick way to check an NPI against the OIG LEIE and loaded state Medicaid exclusion lists, what a match does and does not mean, and where to verify before acting.
What NPI taxonomy codes are, how the NUCC classification works, primary vs secondary taxonomies, and why a taxonomy is a self-reported classification — not a license.
What a complete NPI lookup should show: the live NPPES record plus the public Medicare signals the registry itself never carries — enrollment, opt-out, and exclusion review signals.