MBI format on the NMP
06/16/2021 | 10:14 AM
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. In order 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.