Assessing the impact of coverage gaps in the Medicare Part D drug benefit.

(1) Medicare beneficiaries reduced their drug spending in response to interruptions in prescription coverage prior to the implementation of the Part D benefit. (2) Interruptions in drug coverage were amplified, as a response to gaps in prescription drug coverage, for those suffering from chronic conditions. (3) Trends in spending and medication utilization by Medicare beneficiaries in this study illustrate how Part D beneficiaries potentially would decrease their medication utilization as a response to increasing gaps in their prescription coverage.