As health care delivery systems take greater responsibility for the costs and quality of care they provide, they should be aware that a patient's ability and willingness to manage their health care is crucial to maximizing outcomes and minimizing costs. According to a Commonwealth Fund–supported study in Health Affairs, patients at a large care delivery system in Minnesota who were identified as the most "activated"—that is, participated in treatment decisions and took part in managing their own care—had significantly lower costs than those who were the least activated.