In response to MGMA member concerns whether new Medicare Beneficiary Identifiers (MBIs) contain the number “0” or the letter “O” on new Medicare cards, CMS clarified that the MBI uses numbers 0-9 and all uppercase letters except for S, L, O, I, B, and Z. As a reminder, starting Jan. 1, 2020, Medicare will only accept the MBI on claims, and practices can access their MBIs via your Medicare Administrative Contractor web portal. Download the member-benefit New Medicare Card Toolkit for additional information on the transition to the new cards and numbers.