Income-related patient cost-sharing: Simulation for prescription drugs under Medicare

This paper studies an application of income-related patient cost-sharing. Using data from the Medicare Current Beneficiary Survey, we find that varying patient costsharing rates with patient income in the Medicare prescription drug program can reduce the severity of two problems: high percent-of-income burdens, and unequal medication due to income. We estimate behavioral responses in the Medicare population and incorporate the estimates into a micro-simulation model which uses data that are representative of the actual Medicare population. We find that introducing incomerelated patient cost-sharing into a Medicare drug program can dramatically reduce the severity of the two problems.