MBI format on the NMP

The Medicare Beneficiary Identifiers (MBIs) are made up of numbers 0 to 9 and upper-case letters A to Z. All letters are used except S, L, O, I, B and Z. To avoid errors when entering the MBI in the Noridian Medicare Portal (NMP), always use the number zero if a “0” character is part of the MBI as the letter “O” is never used. Likewise, with the number “1” and the letters “L” or “I” as only the number 1 is a valid character for the MBI.

To learn more about how the MBI is formatted, visit the Understanding the Medicare Beneficiary Identifier (MBI) Format page on the CMS website.

            Last Updated Wed, 16 Jun 2021 19:10:25 +0000