TY - JOUR AU - Courtemanche, Charles AU - Marton, James AU - Ukert, Benjamin AU - Yelowitz, Aaron AU - Zapata, Daniela TI - Impacts of the Affordable Care Act on Health Insurance Coverage in Medicaid Expansion and Non-Expansion States JF - National Bureau of Economic Research Working Paper Series VL - No. 22182 PY - 2016 Y2 - April 2016 DO - 10.3386/w22182 UR - http://www.nber.org/papers/w22182 L1 - http://www.nber.org/papers/w22182.pdf N1 - Author contact info: Charles J. Courtemanche Department of Economics Gatton College of Business and Economics University of Kentucky Lexington, KY 40506-0034 Tel: (859) 323-7990 Fax: (859) 323-1920 E-Mail: courtemanche@uky.edu James Marton Georgia State University Andrew Young School of Policy Studies Department of Economics P.O. Box 3992 Atlanta, GA 30302-3992 E-Mail: marton@gsu.edu Benjamin D. Ukert 212 Adriance Lab Rd College Station, TX 77843 E-Mail: benukert@gmail.com Aaron Yelowitz University of Kentucky Department of Economics 225H Business and Economics Building Lexington, KY 40506 Tel: 859/257-7634 Fax: 859/323-1920 E-Mail: aaron@uky.edu Daniela Zapata Impaq International 1325 G Street, NW Suite 900 Washington, DC 20005 E-Mail: dzapata@impaqint.com AB - The Affordable Care Act (ACA) aimed to achieve nearly universal health insurance coverage in the United States through a combination of insurance market reforms, mandates, subsidies, health insurance exchanges, and Medicaid expansions, most of which took effect in 2014. This paper estimates the causal effects of the ACA on health insurance coverage using data from the American Community Survey. We utilize difference-in-difference-in-differences models that exploit cross-sectional variation in the intensity of treatment arising from state participation in the Medicaid expansion and local area pre-ACA uninsured rates. This strategy allows us to identify the effects of the ACA in both Medicaid expansion and non-expansion states. Our preferred specification suggests that, at the average pre-treatment uninsured rate, the full ACA increased the proportion of residents with insurance by 5.9 percentage points compared to 3.0 percentage points in states that did not expand Medicaid. Private insurance expansions from the ACA were due to increases in both employer-provided and non-group coverage. The coverage gains from the full ACA were largest for those with incomes below the Medicaid eligibility threshold, non-whites, young adults, and unmarried individuals. We find some evidence that the Medicaid expansion partially crowded out private coverage among low-income individuals. ER -