CMS Pub. 100-06, ch. 6, § 440.6

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 carrier controls all claims from which it extracts MSP savings and is able to verify all amounts

recorded on the CMS-1564.

MSP Savings File - The carrier retains claims specific key identifying information on each claim

counted as savings on the CMS-1564. At a minimum, it records the beneficiary's name, Medicare

beneficiary identifier, claim control number, type/dates of service, billed charges and savings

amounts reported.

Savings Data from Non-Medicare Sources - If the carrier records savings from data which it has

obtained from its "private side" records or any other "outside" source, it must be able to extract the

same claims specific information noted above; i.e., it must verify that Medicare covered services

are involved and be able to calculate "what Medicare would have paid." In addition, it compares

these data with the data contained in its MSP savings file to ensure that savings have not

previously been recorded for the same claim. If savings have not previously been taken, it counts

them as savings on the CMS-1564 and enters them into its MSP savings file.

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