Each quarter, Health Affairs reports on new developments in four sectors of the health sphere: health care innovation in Summer; national health care spending in Fall; health personnel in Winter; and health status and health care utilization in Spring. In this issue, Michael R. Pollard and Gary S. Persinger, both of the Pharmaceutical Manufacturers Association, report on recent trends in health research and development. Ira Burney and Julia Paradise, of the Health Care Financing Administration, offer the latest data on Medicare physician participation and assignment rates. The next DataWatch by Janet Mitchell, of the Massachusetts-based Center for Health Economics Research, and colleagues discusses reform of the Medicare physician reimbursement system. The section concludes with a study of long-term care IRAs by University of California, San Diego researchers Dennis E. Smallwood, Harold J. Simon, and Barbara L. Brody.