NPI Validator
Paste an NPI to check whether its check digit is correct.
Computed locally in your browser with the standard NPI Luhn check-digit scheme over the 80840 issuer prefix. Your NPI stays only on this page.
Validate an NPI check digit
Paste a 10-digit US National Provider Identifier to confirm its check digit and read off the corrected value when the digit is wrong. A valid NPI starts with 1 or 2, and its last digit is the Luhn modulus-10 check digit computed after prepending the constant 80840 issuer prefix to the first nine digits. Surrounding spaces and hyphens are ignored. Need to create valid fixtures instead? Try the NPI generator.