In order to ensure the MSP refund is properly processed, a copy of the other insurer’s EOB and/or payment information (i.e., a copy of the check) is required to calculate the Medicare Secondary payment. When the Medicare Secondary payment is calculated, it will determine if the refund amount is correct or there is an additional balance due.

However, if the other insurer’s EOB is not received or information on the primary does not match all the detail line on the Medicare claim, the entire claim and/or detail line will be processed as a full denial.  This could result in a balance due to Medicare, demandable debt, with no Medicare secondary consideration.