There is a need for stronger Federal assistance to States for radiation emergency response planning. This report discusses the status of State radiation emergency response plans and the improvements needed in the Federal interagency effort to get State and local governments to improve their plans. Since 1973 the Nuclear Regulatory Commission (NRC) has led a Federal interagency effort in assisting States to develop radiation emergency plans for incidents at nuclear facilities and accidents involving transportation of radioactive materials. In an evaluation of State radiation emergency plans, NRC found that most of the States had the following problems: poorly developed relationship to general State emergency plans; vague concept of operations; fragmented organization; inadequate provisions for accident assessment, protective response, and medical support; not integrated with plans of contiguous States; and unclear relationship between State and local plans. GAO reviewed four State plans that disclosed several areas requiring more attention: inadequate training of State and local officials involved in radiation emergency activities; inadequate testing of plans by the States, although State officials acknowledged the need for comprehensive testing; and weak coordination between State and local assist agencies in defining authority and responsibility.