Guides & references

Understand NPIs, end to end

Plain-English explainers for patients, billers, and providers: what NPI numbers are, how to look them up, and how the CMS registry works.

The basics

What is an NPI number? Format, the Luhn check digit, and who needs one. Type 1 vs Type 2 NPIs Individual vs organization numbers, and when you need both. What is the NPI registry (NPPES)? A plain-English guide to the official CMS database. NPI vs Tax ID vs DEA vs CLIA The healthcare ID numbers, explained side by side. What is a credential on an NPI record? MD, DO, NP and other letters after a provider's name. What does a deactivated NPI mean? Why a number shows as inactive, and what it implies.

How-to

How to find a provider's NPI A step-by-step free lookup walkthrough. Verify a provider's license & NPI Confirm a record is real, current, and correct. How to apply for an NPI The free NPPES application, step by step. Update or deactivate an NPI Changing an address, name, or status on file. NPI lookup by phone number How it works, and its real limits. What is a taxonomy code? How specialties are encoded, like 207Q00000X.

Roles & billing

Popular Do nurses need an NPI? RN vs NP enumeration, explained. NPIs for medical billers How billing teams use the registry on claims. Group NPI vs individual NPI Billing and rendering providers on a claim. How often is NPI data updated? NPPES refresh cadence and what it means for you. What is a PTAN? The Medicare-only number, and where to find yours. Medicare conversion factor How the CF turns RVUs into dollars, with 2026 values. Validate an NPI → Check a 10-digit number's check digit instantly.