A/B MAC (A), (B), or (HHH) or DME MAC Learns Beneficiary

10.10 - A/B MAC (A), (B), or (HHH) or DME MAC Learns Beneficiary is an HMO Enrollee (Rev. 3441, Issued: 01-15-16, Effective; 12-31-13; ASC X12: 01-01-12, MAC Implementation: 02-16-16; ASC X12: 02-16-16) If the A/B MAC (A), (B), or (HHH), or DME MAC determines from its records or its query to CMS that a patient is an HMO enrollee, the MAC will return the claim to the provider with instructions to request payment from the HMO for payment, if appropriate.