The vast majority of Part D plans follow a tiered cost-sharing structure with incentives for members to use less expensive generic and preferred brand-name drugs. Cost-sharing has increased since 2006, but the Kaiser Family Foundation reports in “Analysis of Medicare Prescription Drug Plans in 2011 and Key Trends Since 2006” that there was barely a change between 2010 and 2011.” The foundation reports that since 2006, median cost sharing for a 30-day supply of nonpreferred brand name drugs in stand-alone prescription drug plans (PDPs) increased by 42 percent, from $55 to $78. Preferred brand costs increased 50 percent, from $28 to $42. But since 2010, cost sharing has been stable.
About half of PDP enrollees and over 75 percent of MA-PD plan enrollees are in plans that charge 33 percent coinsurance for specialty drugs. Compared to 2009, this share is down modestly for PDPs but up substantially for MA-PD plans. In contrast, only 4 of the 35 national or near-national PDPs charged a 33 percent coinsurance rate for specialty tier drugs in 2006.