Healthcare System models and simulations may be used to support analysis, planning, and training needs for the healthcare institutions, epidemics, and other healthcare-related emergencies. Simulation models may be used to understand healthcare systems, interdependencies with other systems, their vulnerabilities, and the impact of emergency incidents on the population and healthcare community. These models and simulations will also be used to support training exercises, performance measurement, conceptual design, impact evaluation, response planning, analysis, acquisition, conceptualizing and evaluating new systems, vulnerability analysis, economic impact, and determining interdependencies between healthcare and other infrastructure systems. The goal of this document is to capture the current knowledge and information resources that can serve as a common baseline for researchers and developers of models and simulations of healthcare systems for homeland security applications. This initial version of the document attempts to assemble relevant, publicly available information from a number of sources within U.S. Department of Homeland Security (DHS) and the modeling and simulation (M&S) communities.