In 2008, in an effort to provide helpful information to consumers and improve provider quality, the Centers for Medicare & Medicaid Services (CMS) developed and implemented the Five-Star Quality Rating System (Five-Star System). The Five-Star System assigns each nursing home an overall rating and three component ratings—health inspections, staffing, and quality measures—based on the extent to which the nursing home meets CMS’s quality standards and other measures. The rating scale ranges from one to five stars, with more stars indicating higher quality. This book examines how CMS developed and implemented the Five-Star System and what key methodological decisions were made during development; the circumstances under which CMS considers modifying the Five-Star System; and the extent to which CMS has established plans to help ensure it achieves its goals for the Five-Star System.