Medicare expenditures attributable to smoking in 1993 were estimated using a multivariate model that related expenditures to smoking history, health status, and the propensity to have had a smoking-related disease, controlling for sociodemographics, economic variables, and other risk factors. Smoking-attributable Medicare expenditures are presented separately for each State and by type of expenditure. Nationally, smoking accounted for 9.4 percent of Medicare expenditures--$14.2 billion, with considerable variation among States. Smoking accounted for 11.4 percent of Medicare expenditures for hospital care, 11.3 percent of nursing home care, 5.9 percent of home health care, and 5.6 percent of ambulatory care.