Under Medicare's tangled payment system, hospitals get higher reimbursements than individual doctors for cardiology treatment, as they do for other specialty services, in some cases as much as 3 times more. At the same time, the added bargaining power gained by controlling more of the heart care in a geographic market has given large hospital systems added leverage in negotiating reimbursements from insurers. In WI, the number of heart doctors in private practice has declined to 11% from 62% of cardiologists in 2007, according to the American College of Cardiology (ACC). The trend is similar nationwide. The number of heart doctors working for US hospitals has more than tripled, while the number in private practice has fallen 23% over 5 years, the ACC said.