Although there are large-scale forces that influence the economic behavior of the health care delivery system, it is the physician who has primary authority to make decisions about the use of resources. Consequently, when considering alternative options for controlling rising health care expenditures, it is useful to examine strategies that focus on promoting efficient physician practice habits. This article reviews the role of the physician as a contributor to the health care cost problem and the state of physician cost-control strategies relative to laboratory testing in confronting this national problem. Five intervention strategies in use are explored: 1) educational strategies intended to improve ordering behavior by increasing knowledge of clinical utilities of tests and procedures in relation to their costs, 2) feedback strategies to compare actual ordering behavior with ordering protocols, 3) cost-awareness strategies, 4) rationing strategies, and 5) market-oriented financial incentives and risk-sharing plans to prompt decreased utilization of diagnostic tests and procedures. Prospects for these strategies are discussed as well.