Patients with complex health care needs account for a high percentage of annual medical expenditures. Care management is a set of activities intended to improve patient care and reduce the need for medical services by helping patients and caregivers more effectively manage health conditions. This synthesis reviews the evidence on care management and its ability to improve patient care and reduce costs. Key findings include: care management can improve quality of care, although it takes time; studies that followed patients longer were more likely to reveal improvements. Care management’s impact on cost reduction is less consistent. Programs that support patient transitions from hospital-to-home were the most successful because they reduced hospital readmissions. Care management within primary care settings may also generate savings. Elements of effective programs include: good identification of patients who could benefit from care management; specially-trained RN/care managers with low patient loads, working with physicians and a multidisciplinary team; and in-person patient contact. Finally, the current fee-for-service systems present barriers to widespread use of care management.