Providing care for individuals with significant medical needs disproportionately drives the cost of medical care in the United States. In fact, 5 percent of patients in the U.S. account for nearly half of all health care spending. This population of high-need patients includes a diverse group of people with multiple chronic diseases and varying levels of medical, functional, social, and psychological complexity. Improving care management and outcomes for this vulnerable population, while also considering the cost of care, is possible. But it requires the active involvement of and a coordinated effort from a broad range of stakeholders across the health care continuum, and must include the integration of medical and social services. In Effective Care for High-Need Patients: Opportunities for Improving Outcomes, Value, and Health, a Special Publication from the National Academy of Medicine (NAM) developed in partnership with the Peterson Center on Healthcare, experts provide insight into care models for high-need patients that have proven results, describe a taxonomy for segmenting the high-need patient population to better match patient need with effective care approaches, and identify opportunities for improving care delivery across multiple sectors.