Margetuximab-cmkb (Margenza) (CPB 0985, reviewed 2026-05-27)

Immediately: Billing team must implement mandatory precertification for Margetuximab-cmkb (Margenza) claims. Update billing system to require prior authorization before claim submission through Aetna at (866) 752-7021 or fax (888) 267-3277. Configure system to enforce coverage criteria: claims only approved for HER2-positive breast cancer patients with either (1) no response to preoperative systemic therapy OR (2) recurrent/unresectable/metastatic disease, AND who have received two or more prior anti-HER2 regimens. Reject claims that do not meet these criteria or lack precertification authorization. Update provider encounter forms to include documentation of prior anti-HER2 treatment regimens (must show ≥2 prior regimens). Train oncology and billing staff on new authorization process and clinical criteria. Update denial management protocols to indicate 'precertification not obtained' for any claims submitted without prior authorization. Failure to obtain precertification will result in claim denials per Aetna policy requirements.