Improving access to high-quality medical care for patients with mental illness remains one of the most vexing problems facing the healthcare system in the United States. As a way to highlight key data on the health and economic impact of Medicaid and other federal policies in expanding access to care, coverage and utilization, the Behavioral Health & Economics Network, in collaboration with its research partners at the University of Southern California Schaeffer Center for Health Policy & Economics, have published a series of chartbooks for each participating state outlining the prevalence and impact of untreated mental illness in these states. The chartbooks are used by clinicians, administrators, advocates, and policymakers to inform state policy advocacy activities.