In September 2013, the OIG issued a report on changes in the use of Medicare Part B ambulance transports from 2002 through 2011, including an analysis of the characteristics of beneficiaries, suppliers, and transports. The report found that between 2002 and 2011, the number of ambulance transports increased by 69%, payments for ambulance transports increased by 130%, and the number of beneficiaries who received ambulance transports increased by 34%. All of these increases were greater than the rates for Medicare Part B increases in general. Moreover, beneficiaries with end stage renal disease received a growing and disproportionate amount of transports, with dialysis-related ambulance transports increasing by 269%. In addition, beneficiaries receiving ambulance transport to outpatient visits for partial hospitalization program services at community mental health centers increased significantly. Overall, the number of ambulance suppliers increased 26% between 2002 and 2011, with those primarily providing basic life support nonemergency transports nearly doubling. The OIG also reports that while all states experienced increases in transports from 2002 to 2011, utilization changes varied widely by state, with high utilization growth linked to dialysis-related transports, basic life support nonemergency transports, and inpatient hospital visits to treat renal failure. The OIG attributes spending increases in part to inflation and the transition to the national fee schedule for Medicare ambulance transports, as well as continued growth in the use of ambulance transports. The OIG did not determine whether the utilization changes it observed were appropriate. Given that prior OIG reports have indicated that ambulance transports are vulnerable to fraud and abuse, however, the OIG does plan to issue a future report focusing on ambulance transport suppliers that exhibit questionable billing characteristics and the geographic areas in which they are concentrated.