The prospect of a bioterrorist attack and the actual anthrax attacks have changed public health in the United States, which in the past has been considered primarily the business of the States. The deliberate release of a harmful biologic agent to intimidate civilians and their government is a threat to public health that differs from any other public health threat that the country has faced. An act of bioterrorism is both a State and Federal crime, and it can also be an act of war. Communicable diseases can be widely spread in a short period of time because of highly developed transportation systems. All of these factors make bioterrorism an inherently Federal matter under the national defense and commerce clauses of the Constitution. The Centers for Disease Control and Prevention (CDC) has released a proposed model act for the States called the Model State Emergency Health Powers Act in October 2001. According to the Act’s provisions, public health personnel have exceptionally broad powers, and failure of physicians and citizens to follow their orders is a crime. The model act poses several problems: (1) the authority to respond to a bioterrorist attack or a new epidemic is much too broad; (2) it may not make sense to put public health officials in charge of responding to every type of bioterrorist event; (3) there is no evidence that physicians or members of the public are reluctant to cooperate during a bioterrorist attack; and (4) a quarantine law should be a Federal law, not a State law. The act is based on the belief that in public health emergencies, there must be a trade-off between the protection of civil rights and effective public health interventions. Although the revised act of December 2001 can be viewed as a modest improvement, all the fundamental problems remain. Bioterrorism is primarily a Federal, not a State, issue, and actions undertaken to prevent and respond to it should be a Federal priority. 32 references