CMS has posted the Medicare Part B average sales price (ASP) payment files for the second quarter of 2011. CMS continues to characterize drug prices in the market as “stable,” with prices for the top Part B drugs decreasing by an average of 0.4%. CMS attributes decreased prices to "a number of competitive market factors at work – multiple manufacturers, alternative therapies, new products, recent generic entrants, or market shifts to lower priced products."