Medicare Claims Processing Manual (Pub. 100-04), Ch. 2 § 10.1
Medicare beneficiary identifiers
10.1 - Medicare beneficiary identifiers
(Rev. 4247, Issued: 03-01-19, Effective: 04-01-19, Implementation: 04-01 -19)
The term Medicare beneficiary identifier (Mbi) is a general term describing a
beneficiary's Medicare identification number. For purposes of this manual, Medicare
beneficiary identifier references both the Health Insurance Claim Number (HICN) and
the Medicare Beneficiary Identifier (MBI) during the new Medicare card transition
period and after for certain business areas that will continue to use the HICN as part of
their processes.
The CMS maintains the electronic records for individuals enrolled in the health insurance
program. The CMS issues health insurance cards where entitlement is established
through the Social Security Administration (SSA), and the Railroad Retirement Board
(RRB) issues health insurance cards where entitlement is established through RRB.
See Chapter 2 of the Medicare General Information, Eligibility, and Entitlement Manual
(Pub. 100-01) for an extended discussion of HI cards and Medicare beneficiary
identifiers.