The Strategic National Stockpile (SNS) can deliver large quantities of medications and medical supplies to anywhere in the United States and its territories within 12 hours of the federal decision to deploy. As an additional preparedness measure, many states and regions have elected to purchase and maintain similar medical countermeasure stockpiles locally. Theses stockpiles are a means of rapid access to critical medications necessary for use as post-exposure prophylaxis (PEP) before the arrival of SNS assets. To assist state and local communities in determining the most efficient and cost effective PEP model for use in the event of an anthrax attack, this book analyzes four potential models. This analysis provides a framework by which state and local jurisdictions can evaluate the suitability of models for the provision of PEP in the event of a large-scale anthrax attack. Readers may employ these findings in evaluating the efficacy of their own local programs, and in determining the most appropriate PEP model based upon local priorities given variations in perceived needs and resource availability among communities.