Supporting Value-Based Health Care - Aligning Financial and Legal Accountability

US health care payment and delivery-system reforms have focused on improving care by making organizations accountable for outcomes, quality, and costs. Payers have supported the implementation of accountable care organizations (ACOs), bundled-payment models, and other value-based payment reforms because they believe that holding health care systems accountable for population-level costs and quality will be more effective than focusing accountability at the physician level. Evidence suggests that these models have increased value but have underperformed relative to the aspirations for them.