CMS Pub. 100-05, ch. 3, § 10.6

If A/B MACs and DME MACs, including the MSP Contractor notify the provider, physician, or

other supplier, or the provider, physician, or other supplier learns from other sources that an

employer plan may be primary payer for services for which Medicare paid primary benefits, the

provider, physician, or other supplier takes the following actions:

• Determines whether there is GHP coverage and, if so, the name and address of

the GHP, if that information is not annotated on the claim;

• Checks its records to confirm whether Medicare paid primary benefits for other

services rendered during a coordination period for which a GHP may be primary;

and

• Notifies the MSP Contractor of the results of the development efforts according

to Pub. 100-05, Chapter 5 Contractor MSP Claims Processing Requirements.

This information is necessary for Medicare to determine its proper payment. If the GHP pays or

has already paid the provider, physician, or other supplier for all or part of the services, the

provider, physician, or other supplier submits a corrected bill to the A/B MACs and DME MACs

along with the GHP’s explanation of benefits (EOB) or remittance advice if the claim is

submitted hardcopy. The A/B MACs and DME MACs recoups from the provider, physician, or

other supplier the amount of Medicare benefits paid in excess of any amount it is obligated to

pay as secondary payer.