The GAO review involved the Department of State, the Department of Defense, the U.S. Secret Service, the Federal Bureau of Investigation, the Federal Emergency Management Agency, the Department of Health and Human Services, the Environmental Protection Agency, the Department of Energy, and the Department of Veterans Affairs, as well as the Bureau of Alcohol, Tobacco, and Firearms. The number of counter-terrorism exercises more than tripled over the 3-year period, with the largest increase in the last year. Agencies used various types of exercises and scenarios. More than half the exercises were field exercises where command and response personnel actually deployed with their equipment, and the rest were tabletop exercises where personnel discussed a particular scenario. Very few exercises included no-notice deployments of personnel and equipment. Over half the exercises dealt with managing the immediate crisis resulting from a terrorist incident, including stopping a terrorist attack. The others dealt with managing the consequences of a terrorist incident, such as caring for the injured. More than two-thirds of the exercises had weapons of mass destruction (WMD) scenarios, while the others had more traditional and more likely terrorist scenarios involving conventional arms and explosives. Over half the WMD exercises used scenarios involving chemical agents. More than two-thirds of the exercises included more than one Federal agency, and almost half the exercises included three or more Federal agencies. 16 references and 21 figures