The Medicare Part D Coverage Gap, Prescription Use, and Expenditures.

The Affordable Care Act has put in place policies to gradually close the Medicare Part D coverage gap (donut hole). I examine the effect of this gradual closure on total and out-of-pocket prescription drug expenditures, as well as the number of prescriptions filled. The analysis shows a general increase in prescription use. There are also heterogeneous effects, with higher total expenditure groups seeing a decrease in their out-of-pocket prescription expenditures. This suggests that closure of the "donut hole" has led to an increase in prescription use that was previously curtailed and had an impact on the financial risk faced by Medicare recipients. This has implications for trends in prescription use and Medicare expenditures in the future, as the coverage gap is closed further.