Health insurers are under conflicting pressures to improve the quality and moderate the costs of health care yet to refrain from interfering with decision making by physicians and patients. This paper examines the contemporary evolution of medical management, drawing on examples from UnitedHealth Group, WellPoint Health Networks, and Active Health Management. It highlights the role of claims data, predictive modeling, notification requirements, and online enrollee self-assessments; the choice between focusing on behavior change among patients or among physicians; and the manner in which medical management is packaged and priced to accommodate the diversity in willingness to pay for quality initiatives in health care.