Outbreaks of infectious diseasesâ€such as Ebola, Zika, and pandemic virusesâ€have raised concerns from Congress about how federal agencies use modeling to, among other things, predict disease distribution and potential impacts. Chapter 1 discusses emerging infectious diseases, in light of the recent coronavirus outbreak, and the modeling tools used to detect, predict, and understand the spread of such diseases. Chapter 2 examines the extent to which HHS used models to inform policy, planning, and resource allocation for public health decisions; the extent to which HHS coordinated modeling efforts; steps HHS generally takes to assess model development and performance; and the extent to which HHS has addressed challenges related to modeling.