The Affordable Care Act marks a new frontier in how healthcare will be delivered in the United States. What role can evaluation play in supporting the kinds of transformations needed to expand access, promote innovation, and improve the health of individuals and communities? This session from Harder+Company Community Research compared and contrasted approaches used to evaluate two different health systems improvement efforts: a hospital readmissions reduction initiative undertaken by L.A. Care (currently the nation’s largest public health plan) and implementation of California’s first Accountable Care Organization. The session highlighted the role of evaluation in informing health systems improvement, including what types of evaluation approaches are best suited to different efforts.#HealthEvaluation #2013Conference