[en] Multiagency exercises were an important part of the development of the Federal Radiological Emergency Response Plan. This paper concentrates on two of these exercises, the Federal Field Exercise in March 1984 and the Relocation Tabletop Exercise in December 1985. The Federal Field Exercise demonstrated the viability and usefulness of the draft plan; lessons learned from the exercise were incorporated into the published plan. The Relocation Tabletop Exercise examined the federal response in the postemergency phase. This exercise highlighted the change over time in the roles of some agencies and suggested response procedures that should be developed or revised. 8 refs