This catalog compiles information from 54 studies of 39 family-strengthening programs that serve low-income couples. It documents the research on the programs’ effectiveness or impacts and the degree to which the studies demonstrate that a specific program (and not some other factor) led to the results. It also describes key program elements—such as content, design, and staffing—as well as implementation and the challenges and successes experienced in recruiting and serving low-income couples. Studies are rated high, moderate, low, and unrated based on design, execution, and analysis.