A phone call to the customer service number listed on the letter may prove successful. If not, the RAC will forward the denied claim(s) to the MAC for an adjustment. Your facility can expect to be notified via a demand letter from the MAC. The letter is to inform you that a Medicare payment was made in error as determined by the Recovery Audit Contractor, along with the amount that should be repaid to Medicare. Fortunately, if you disagree with the overpayment decision, you may file an appeal. The first level appeal, the redetermination request, must be filed within 120 days from the date of the demand letter. However, in order to avoid recoupment, you will need to file the redetermination request within 30 days. For more information about the Recovery Audit Program, access the CMS Recovery Website here.