Understanding The Effects of The Medicare Part D Coverage Gap in 2008 and 2009

This Kaiser Family Foundation study examines how the coverage gap in Medicare’s drug benefit known as the “doughnut hole” affects Medicare beneficiaries and their prescribing patterns.

Based on actual claims data from 2008 and 2009, before the 2010 health reform law began to close the gap, the study finds that most Part D enrollees with high drug costs who fall in the gap one year are likely to do so in future years. Enrollees who take drugs for certain conditions, including breast cancer and Alzheimer’s drugs, are more likely to reach the gap than other beneficiaries.

The report analyzes retail pharmacy claims data compiled by IMS Health, and was conducted jointly by Jack Hoadley and Laura Summer of Georgetown University, Elizabeth Hargrave of NORC at the University of Chicago, and Juliette Cubanski of the Kaiser Family Foundation.