Abstract Five percent of the patient population accounts for 50% of U.S. healthcare expenditures. High-need, high-cost patients are medically complex for numerous reasons, often including behavioral health needs. Intensive outpatient care programs (IOCPs) are emerging, innovative clinics which provide patient-centered care leveraging multidisciplinary teams. The overarching goals of IOCPs are to reduce emergency department visits and hospitalizations (and related costs), and improve care continuity and patient outcomes. The purpose of this review was to examine the effectiveness of IOCPs on multiple outcomes to inform clinical care. A systematic search of the literature was conducted to identify articles. Six studies were included that varied in rigor of research design, analysis, and measurement of outcomes. Most studies reported results on healthcare utilization (n = 4) and costs (n = 3), with fewer reporting results on patient-reported and health-related outcomes (n = 2). Overall, there were decreasing trends in emergency department visits and hospitalizations. However, results on healthcare utilization varied based on time of follow-up, with shorter follow-up times yielding more significant results. Two of the three studies that evaluated costs found significant reductions associated with IOCPs, and the third was cost-neutral. Two studies reported improvements in patient-reported outcomes (e.g., satisfaction, depression, and anxiety). Overall, these programs reported positive impacts on healthcare utilization and costs; however, few studies evaluated patient characteristics and behaviors (e.g., engagement in care) which may serve as key mechanisms of program effectiveness. Future research should examine patient characteristics, behaviors, and clinic engagement metrics to inform clinical practice.