Medicare Part D: Complex Coverage (WebMD)
Medicare Part D prescription drug plans vary widely in their formularies, according to study in The Journal of the American Medical Association.

General Satisfaction with Plan Benefits Found Among Patients Navigating Medicare Part D, According to Study by GfK ... (Business Wire via Yahoo! Finance)
EAST HANOVER, N.J.----Patients participating in Medicare Part D prescription drug coverage are, in general, satisfied with their current plan benefits. Research from GfK Market Measures' Outlook 360: The Impact of Medicare Part D on Patients reveals that patients find obtaining their prescriptions is now fairly easy and that participating in a Part D plan is helping them afford their medications.

Medicare Part D plans vary across U.S. (News-Medical-Net)
An examination of Medicare Part D plans in California and Hawaii reveals wide variations in drug formularies, but indicates that for many classes of drugs, it is possible to find at least one or more drug that is covered by nearly all Part D plans, according to a study in the June 20 issue of JAMA: The Journal of the American Medical Association