Date of Award

January 2020

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Amy J. Davidoff


The original Medicare Part D benefit included a gap in coverage, commonly known as the “doughnut hole,” where beneficiaries were responsible for 100% of drug costs. The Affordable Care Act included provisions to gradually close this gap, beginning in 2011, in order to reduce the financial burden of drug spending for Part D enrollees. Using a nationally representative survey of Medicare beneficiaries, we examined the effect of this policy on out-of-pocket drug spending and medication affordability. We found that the policy was associated with a decrease in out-of-pocket spending. However, this trend was limited to relatively healthy enrollees in stand-alone Part D plans. Surprisingly, measures of medication affordability worsened after closure of the coverage gap. These results highlight persistent problems of medication affordability in the Part D program and underscore the need for policy makers to further address the financial burden posed by medication costs.


This thesis is restricted to Yale network users only. It will be made publicly available on 09/10/2022