Medicare Advantage (Part C) lets private insurers offer Medicare coverage, often with extra benefits (dental, vision, gym memberships) in exchange for accepting capitated payments from CMS. More than half of Medicare beneficiaries are now enrolled in MA plans.
Critics — including MedPAC, the OIG, and many academic researchers — point to evidence of risk-score "upcoding" (insurers coding patients as sicker than they are to collect higher payments), aggressive and sometimes misleading marketing, frequent prior-authorization denials, and total taxpayer costs that exceed what equivalent traditional Medicare would cost.
Defenders point to extra benefits, lower out-of-pocket costs for many enrollees, care coordination, and high member-satisfaction scores. Reform proposals range from incremental adjustments to risk-adjustment formulas up to structural changes in how MA plans are paid and regulated.