In late 2001, during the aftermath of the anthrax letter attacks, model legislation was proposed to relevant state agencies to update their states' public health laws to meet the threat of bioterrorism. This legislation was the Model State Emergency Health Powers Act. A concern underlying this and related efforts to address future bioterrorism threats was the perceived inadequacy of state laws to respond effectively when such threats occur. We evaluated how 4 states--Utah, Maine, South Dakota, and Indiana--addressed this concern in the context of the model legislation. The conclusion is that the model legislation generally served as an important catalyst for state action in the field of bioterrorism preparation.