The report outlines the process and criteria used by the Centers for Disease Control and Prevention (CDC) to prioritize biological agents for public health preparedness efforts in response to potential biological terrorism. The selection and prioritization process involved a meeting of national experts who reviewed various lists of biological agents and applied criteria such as public health impact, delivery potential, public perception, and special public health preparedness needs. Agents were categorized into three priority levels (A, B, and C) based on their overall evaluation in these areas. Category A agents pose the greatest threat with potential for mass casualties and large-scale dissemination, requiring broad-based public health preparedness efforts. Category B agents have some potential for large-scale dissemination but cause less illness and death, necessitating improved awareness and surveillance. Category C agents are emerging threats or those that do not currently pose a high bioterrorism risk but could become significant in the future. The report emphasizes the need for ongoing evaluation and prioritization of biological agents to address evolving threats and ensure effective public health preparedness.The report outlines the process and criteria used by the Centers for Disease Control and Prevention (CDC) to prioritize biological agents for public health preparedness efforts in response to potential biological terrorism. The selection and prioritization process involved a meeting of national experts who reviewed various lists of biological agents and applied criteria such as public health impact, delivery potential, public perception, and special public health preparedness needs. Agents were categorized into three priority levels (A, B, and C) based on their overall evaluation in these areas. Category A agents pose the greatest threat with potential for mass casualties and large-scale dissemination, requiring broad-based public health preparedness efforts. Category B agents have some potential for large-scale dissemination but cause less illness and death, necessitating improved awareness and surveillance. Category C agents are emerging threats or those that do not currently pose a high bioterrorism risk but could become significant in the future. The report emphasizes the need for ongoing evaluation and prioritization of biological agents to address evolving threats and ensure effective public health preparedness.