The researchers examined changes in integration between hospitals and post-acute care (PAC) providers and assessed the effect of integration on patient outcomes. In the first part of the study, the researchers examined changes in integration over time and described how this integration changed with the introduction of accountable care organizations (ACOs), focusing on the three most common types of PAC providers: skilled nursing facilities, inpatient rehabilitation facilities, and home health agencies. The analysis considered both vertical integration (hospital ownership of PAC providers) and patient-flow-based integration (observed patterns of patient discharges from hospitals to PAC providers). The researchers then examined how changes in integration and ACO participation affected hospital readmissions and total costs of care. The goal of this project was to help inform policymakers, health care administrators, and patients about the effects of integration between hospitals and PAC providers on the quality and efficiency of care.