The National Roundtable on Health Care Quality was organized in 1996 by the Institute of Medicine and consisted of broad representation from business, education, government, the media, and health care. This 1998 consensus report articulates a definition of health care quality and indicts the US health care system for significant systematic failures to deliver high-quality care, giving several illustrative examples. The report offers a tripartite classification system—underuse, overuse, and misuse—for lapses in quality and discusses the impact of each on outcomes and health expenditures. The authors review existing efforts to improve quality, including regulation, "Continuous Quality Improvement," market forces, and payment incentives. Without prescribing a specific approach, the authors call on health care professionals to take the lead in a national health care quality improvement effort.