In an effort to protect Medicare beneficiaries against the increasing prevalence of fraud and identify theft, CMS (Center for Medicare and Medicaid Services) will issue a unique, randomly assigned Medicare Beneficiary Identifier (MBI) to 57 million Medicare beneficiaries. This card will include a combination of 11 characters; either uppercase letters from A to Z, (except for S, L, O, I, B, and Z — for ease of reading) and numbers 0-9. The new cards will no longer contain one’s social security number.
Issuance of the new MBI cards will begin April 1, 2018 with expected completion by April 2019, and a transition period through Dec. 31, 2019, which means those enrolled in Medicare will be permitted to use their old Medicare card or their new MBI card. After Dec. 31, 2019, beneficiaries must use the new MBI cards.