Medical ethics generally applies to individual interactions between physicians and patients. Conversely, public health ethics typically applies to interactions between an agency or institution and a community or population. Four main principles underlie medical ethics: autonomy, nonmaleficence, beneficence, and justice. By contrast, public health ethical principles address issues such as interdependence, community trust, fundamentality, and justice. In large part because of the significant community-level effects of public health issues, medical ethics are suboptimal for assessing community-level public health interventions or plans—especially in the area of emergency preparedness. To be effective, as well as ethical, public health preparedness efforts must address all of the core principles of public health ethics.