The State Health Care Spending Project, a collaboration between The Pew Charitable Trusts and the John D. and Catherine T. MacArthur Foundation, examined seven major areas of state health care spending—Medicaid, the Children’s Health Insurance Program, substance abuse treatment, mental health services, prison health care, active state government employee health insurance, and retired state government employee health insurance. The project provided a comprehensive examination of each of these health programs that states fund. The programs vary by state in many ways, so the research highlighted those variations and some of the principal factors driving them. The project concurrently released state-by-state data on 20 key health indicators to complement the programmatic spending analysis. To see new research from Pew on prison health care spending, please visit State and Local Correctional Health Care Spending.