NPI number checker
Check whether a 10-digit number is formatted like a real NPI. This catches typos instantly, without searching the registry.
Try , a sample that passes the test.
What this test does
The last digit of every NPI is a check digit worked out from the first nine. If you mistype one digit, the check usually fails. It tells you a number is well-formed; it can't tell you the number was issued. To find out who has it, look it up.
Read how the check digit works, with a worked example.