The US government manages a large number of data sets, including federally funded data collection activities that examine infectious and chronic conditions, as well as risk and protective factors for adverse health outcomes. Although there currently is no mature, comprehensive metadata repository of existing data sets, US federal agencies are working to develop and make metadata repositories available that will improve discoverability. However, because these repositories are not yet operating at full capacity, researchers must rely on their own knowledge of the field to identify available data sets. We sought to identify and consolidate a practical and annotated listing of those data sets. Creative use of data resources to address novel questions is an important research skill in a wide range of fields including public health. This report identifies, promotes, and encourages the use of a range of data sources for health, behavior, economic, and policy research efforts across the life span. We identified and organized 28 federal data sets by the age-group of primary focus; not all groups are mutually exclusive. These data sets collectively represent a rich source of information that can be used to conduct descriptive epidemiologic studies. The data sets identified in this article are not intended to represent an exhaustive list of all available data sets. Rather, we present an introduction/overview of the current federal data collection landscape and some of its largest and most frequently utilized data sets.