A proposal to limit beneficiaries' costs for traditional Medicare's core services and reduce the need for supplemental coverage is the focus of a Commonwealth Fund report by Cathy Schoen, Karen Davis, Christine Buttorff, and Amber Willink. The researchers propose capping annual out-of-pocket expenses for Parts A and B benefits and replacing hospital cost-sharing with a per admission copayment — reforms, the authors say, that would put traditional Medicare on a more equal footing with private Medicare Advantage plans.