During the national health care reform debate in the 103rd Congress, all major proposals included specific clinical preventive services as important and explicitly defined benefits. The proposed Health Security Act, for example, carefully defined a benefit package with selected clinical preventive services. Even more modest proposals frequently specified elimination of co-payments for preventive care. While no health care reform legislation was passed by the 103rd Congress, support for preventive services, in one way or another, was one of the few nearly universally accepted goals. Today, health care purchasers and consumers appear to be demanding more accountability in health care delivery systems.1 There is growing interest in reporting health care plan performance, including performance of clinical preventive services. For example, the Healthplan Employer Data and Information System (HEDIS) is used by many managed care plans, and is being required for Medicare managed care plans.2 HEDIS includes data on a significant number of clinical preventive services, such as immunizations, mammography, lipid screening, and cervical cancer screening. Comparisons among plans can be made by potential purchasers and consumers. Plans are competing in terms of clinical prevention as well as acute care services and cost. A new focus on these preventive services is provided by the rapid increase in the proportion of Americans receiving care in organized delivery systems. Although other services, such as counseling and injury prevention, have not received the same attention, preventive care, nevertheless, remains in the national spotlight. Health care organizations that are accountable for providing care to a defined population would appear to have a vested interest in shifting the focus of medical care to one that keeps individuals as healthy as possible. On the other hand, rapid enrollee turnover may lessen managed care’s interest in preventive services, as the benefits may not accrue until years later, when the enrollee may be in another plan. Fierce competition among plans may require them to focus on current cost reduction rather than on long-term benefits. And even if they did focus on future costs, preventive services do not always produce reduced health care costs.3 Preventive services may not expand under managed care unless they are both demanded by purchasers, and can be provided at reasonable cost. While there appears to be national interest in making preventive services widely available, there is, then, also great interest in making them efficient, i.e., making them produce the most good for the least cost. This goal fits into the rubric of health services research. The Agency for Health Care Policy and Research (AHCPR) is the lead agency for health services research in the Department of Health and Human Services. Building on a foundation established by its predecessor, the National Center for Health Services Research, AHCPR has supported studies that identify ways to increase the delivery and efficiency of recommended clinical preventive services.4 In general, clinical preventive services are prevention services offered or initiated in the personal health care setting. Examples include immunizations, disease screening, counseling to reduce health risks, and chemoprophylaxis after exposure to infectious disease. AHCPR-supported studies have focused on a variety of clinical preventive services issues. One study examined barriers to receiving preventive services.5 Another AHCPR-supported study explored ways to increase private physician participation in the Early and Periodic Screening, Diagnosis, and Treatment (EPSDT) program, helping to bring the benefits of a public prevention program to children seen in physicians’ offices.6 Other AHCPR-supported studies currently underway include the development of strategies to encourage primary care practitioners to increase the provision of recommended prevention services. Center for Primary Care Research, Agency for Health Care Policy and Research, Rockville, Maryland 20852. Address correspondence to: Dr. James K. Cooper, CPCR/AHCPR, 2101 E. Jefferson Street, Rockville, Maryland 20852.