Systematically improving the quality of medical care requires the creation and implementation of organized processes by health plans, hospitals, and physician groups. But to a considerable extent the medical market in the United States financially penalizes organizations that invest in improving quality, rather than rewarding them. This article explores the ways in which the market as presently constituted fails to reward investments in quality improvement and describes efforts newly underway to create a "business case for quality." It briefly suggests measures to that could be taken by public and private policymakers--by government as purchaser and regulator of medical care, and by large employers who in effect make policy through their health insurance purchasing decisions--to create a business case for quality.