Medicare physicians' services: the composition of spending and assignment rates.

Medicare spending for physicians' services, the second largest component of the Medicare program (24.5 percent), represents 1.3 percent of the Federal budget, 0.41 percent of the gross national product, and 19.4 percent of national spending for physicians' services. Interest in reforming the Medicare physician payment system is growing. Detailed information on patterns of Medicare spending for physicians' services and assignment rates according to physician specialty, place of service, type of service, and procedure are presented here.