Although managed care plans reduce health care expenditures at any point in time, less is known about whether such plans control health care cost growth. Because use of new medical technology is an important determinant of cost growth, the impact of managed care on utilization of medical technology will largely determine whether managed care can reduce expenditure growth to sustainable levels. This article reviews the literature relating medical technology to cost growth and the literature examining the impact of managed care on either cost growth or on the diffusion of medical technology. Studies that examine plan-level data often reach different conclusions than studies that examine market-level data. The evidence suggests that managed ca...