Health care spending estimates constitute an important public policy tool, providing a broad look at historical trends in unique State health care systems. The State health expenditure estimates presented here detail spending for the 50 States and the District of Columbia for calendar years 1980-1998. They include expenditure estimates for specific service types as well as for two major sources of funding--Medicare and Medicaid. In this article, the authors address health care's role in State economies, trends in major service sectors and payers, and factors influencing these trends.