The GAO has released a report examining Medicare payments and provider costs for ground ambulance services, along with beneficiary utilization of ambulance services. The GAO found that in 2010, costs per transport varied widely among ambulance providers in the GAO’s sample, ranging from $224 to $2,204 per transport, with a median cost of $429. The report discusses the factors impacting these costs, including volume of transports, the proportion of transports that were nonemergency, and the extent to which providers received government subsidies. The median Medicare margin for 2010, including add-on payments, was about 2% for the providers in GAO's sample, but it varied from about -2% to +9%, (without add-on payments, the margin ranged from about -8% to +5%). Medicare utilization levels also have been on the increase, with ground ambulance transports for all Medicare fee-for-service beneficiaries increasing 33% from 2004 to 2010, with the highest growth in super-rural areas. According to the GAO, ambulance provider organization representatives suggested the increase in transports may stem from increased billing by local governments, since some local governments that used to provide Medicare transports free of charge may now be billing Medicare because of budgetary pressures. On the other hand, the GAO notes that the OIG has cited improper payments as a potential cause for increases in Medicare ambulance utilization.