CMS has posted the April 2013 Medicare Part B ASP files.CMS observes that average drug prices in the market generally remain stable, with prices for the top Part B drugs decreasing by 0.5% from the first to second quarter of 2013. Note that unlike other recent quarterly updates, CMS does not provide an update on implementation of average-manufacturer price based price substitutions (CMS previously stated that it was delaying implementation due to “a variety of operational issues”).