Post-acute care (PAC) occurs in a variety of settings-skilled nursing facilities (nursing homes), rehabilitation facilities, and home health agencies. To evaluate the impact of care processes on clinical outcomes and implement changes designed to improve outcomes, one must begin by measuring outcomes in a valid, reliable manner that allows for comparisons to reference or benchmarking data. Currently, several data sets exist in PAC settings for the purpose of outcome measurement. However, there is a need for comparable information across settings to ensure the quality and continuity of care. This article reviews various existing data sets used in PAC settings, examines ongoing projects to create a single set of measures, and suggests some directions for future research.