MARK McCLELLAN, commissioner of the U.S. Food and Drug Administration since November 2002, was nominated February 20 by President George W. Bush to lead Medicare as it heads into its biggest expansion in 40 years. McClellan, an associate professor of economics and of medicine, has been on leave from Stanford since spring 2001, when he joined the Council of Economic Advisers as Bush’s top adviser on health policy. As head of the Centers for Medicare and Medicaid Services, McClellan would oversee more than $600 billion in health-care spending as the nation prepares to expand prescription-drug coverage for the elderly. McClellan must be confirmed by the U.S. Senate Committee on Finance, which oversees Medicare and Medicaid. In a memorandum issued Feb. 20, the committee’s chairman, Sen. Chuck Grassley, R-Iowa, said McClellan is a strong nominee and a nomination hearing would be scheduled as soon as possible.