Today CMS published a notice correcting its November 10, 2014 final rule updating the Medicare Hospital Outpatient Prospective Payment System (OPPS) and the Ambulatory Surgical Center (ASC) Payment System rates and policies for calendar year 2015. In addition to fixing various technical errors (e.g., status indicator and addenda corrections for specific codes), the notice increases the OPPS conversion factor from $74.144 to $74.173, which will slightly increase payment rates for most ambulatory payment classifications. On the other hand, CMS is reducing the 2015 ASC conversion factor slightly, from $44.071 to $44.058.