Most of the evidence regarding the success of ACOs is from the Medicare program. This review evaluates the impacts of ACOs within the Medicaid population. We identified 32 relevant studies published between 2012 and 2023 which analyzed the association of Medicaid ACOs and health care utilization (n = 21), quality measures (n = 18), health outcomes (n = 10), and cost reduction (n = 3). The results of our review regarding the effectiveness of Medicaid ACOs are mixed. Significant improvements included increased primary care visits, reduced admissions, and reduced inpatient stays. Cost reductions were reported in a few studies, and savings were largely dependent on length of attribution and years elapsed after ACO implementation. Adopting the ACO model for the Medicaid population brings some different challenges from those with the Medicare population, which may limit its success, particularly given differences in state Medicaid programs.
Keywords: Medicaid; access/demand/utilization of services; accountable care organizations; health care costs; health care quality.