The Medicare Beneficiary Identifier (MBI) is a unique, randomly generated number that replaces the Health Insurance Claim Number (HICN) on Medicare cards. This identifier is eleven characters long, consisting of numbers and uppercase letters (excluding S, L, O, I, N, B, F, and U to avoid confusion). An example of such a number is 1EG4-TE7-MK72.
Its implementation was mandated by the Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) to reduce the vulnerability of beneficiaries’ Social Security Numbers to identity theft and fraud. The utilization of this new identifier enhances security, simplifies healthcare transactions, and protects sensitive personal data, thereby safeguarding the integrity of the Medicare system and the privacy of its enrollees. Its adoption also marked a significant shift in how Medicare identifies and processes claims for services rendered.