Robert A. Berenson, M.D., is a senior fellow at the Urban Institute. He is an expert in health care policy, particularly Medicare, with experience practicing medicine, serving in senior positions in two administrations, and helping organize and manage a successful preferred provider organization. From 1998 to 2000, he was in charge of Medicare payment policy and managed care contracting in the Health Care Financing Administration (now the Centers for Medicare and Medicaid Services). In the Carter Administration, he served as an assistant director of the domestic policy staff. He was also National Program Director of IMPACS (Improving Malpractice Prevention and Compensation Systems), a grant program funded by the Robert Wood Johnson Foundation, from 1994 to 1998. Dr. Berenson is a board-certified internist who practiced for 12 years in a Washington, D.C., group practice and is a Fellow of the American College of Physicians. Dr. Berenson is also adjunct professor at the University of North Carolina School of Public Health and the Fuqua School of Business at Duke University. He is coauthor, with Walter Zelman, of The Managed Care Blues & How to Cure Them, published in 1998. Dr. Berenson's current research focuses on modernization of the Medicare program to improve efficiency and the quality of care provided to beneficiaries.