Evidence-Based Policymaking Is an Iterative Process: A Case Study of Antipsychotic Use among Children in the Foster Care System – State policymakers must sometimes take action even when relevant, credible evidence identifying the best policy approach may not be available, such as during a recent, emerging crisis impacting the health of children, adults and families. This brief explores successful state responses to dramatic increases in antipsychotic prescription rates in Medicaid-enrolled children, including children in foster care. In August 2018, the National Academy for State Health Policy (NASHP) convened researchers and a cross-agency group of officials with expertise in financing and operating Children’s Health Insurance Program (CHIP) and Medicaid programs, children’s health, and health policy and pharmacy research. Participants from multiple states discussed state strategies to ensure the appropriate use of antipsychotic drugs in youth in foster care. Strategies discussed and shared in this brief include payment reforms, delivery system innovations, and quality supports for clinical care. Other areas for improvement include increasing monitoring rates for side effects, advancing psychosocial and trauma-informed care, enhancing patient engagement, and improving data collection and use