Impacts of the Affordable Care Act Medicaid Expansion on Health Insurance, Health Care Utilization, and Health Outcomes for Mexican Americans

Latinos in the USA are the least likely to have health insurance compared to other racial and ethnic groups. Mexican Americans, the largest subgroup of US Latinos, have particularly great barriers to health care access and experience disparities in care and in health outcomes. The Affordable Care Act (ACA), enacted in 2010 and mostly implemented by January 1, 2014, was designed in part to improve health insurance access for uninsured groups, including an option for states to expand Medicaid. We assess the ACA's effect on six health-related outcomes for Mexican American adults (18-64 years of age). We estimate difference-in-difference models using the IPUMS National Health Interview Survey data; Mexican Americans living in the West are assigned as the treatment group (where similar to 97% of Mexican Americans live in states which expanded Medicaid) and the South as a control group (where similar to 4% of Mexican Americans live in states which expanded Medicaid). We designate 2010-2013 as the pre-treatment period and 2014-2018 as the post-treatment period. The results for the full sample suggest that Medicaid expansion increased Mexican Americans' probability of having health insurance, a physician visit in the past year, and self-reported diabetes, chronic kidney disease, and hypertension; and decreased the probability of reporting self-assessed health of "very good" or "excellent." Heterogeneity analyses suggest remarkably large gains for those who are men, foreign-born, undocumented, with less than high school levels of education, with incomes less than 100% of the federal poverty line (FPL), and those who have lived more than 5 and less than 10 years in the USA.