Providers of ambulance services can gain a bit of insight into how carriers calculate the reasonable charge portion of their blended transitional payments from a Nov. 21 one-time notification (change request 2700) from the Centers for Medicare & Medicaid Services. For new suppliers, the reasonable charge should be the lower of: the supplier's submitted charge, the 50th percentile prevailing charge, and the prevailing inflation-indexed charge, CMS explains. In other recent one-time notifications, CMS: To see the transmittals, go to http://cms.hhs.gov/manuals/transmittals/comm_date_dsc.asp.