This report compares available stand-alone Part D plans, finding significant variation in access to drugs and out-of-pocket (OOP) costs. 

From the report:

Medicare Part D drug plans use formularies (lists of covered drugs), cost sharing, and utilization management techniques to manage enrollees’ use of drugs. As a result, beneficiary access to and out-ofpocket costs for a particular drug can vary widely from one Part D plan to another. This Part D Data Spotlight examines coverage of top brand-name and specialty drugs. The analysis is based on the authors’ analysis of data from all national and near-national stand-alone prescription drug plans (PDPs) offered by Part D sponsors in 2010, representing 91 percent of all PDPs nationwide and about 87 percent of PDP enrollment.

Full Report: Coverage of Top Brand-Name and Specialty Drugs (PDF | 546 KB)

Kaiser Family Foundation. (2010). Coverage of top brand-name and specialty drugs. Hargravei, E., Hoadley, J., Summerii, L., Cubanski, J., and Neumaniii, T.