OBJECTIVES

: This study aimed to examine changes in insurance coverage and assess the effects of Medicaid expansion on poverty disparity in insurance coverage in the United States.

METHODS

: Data from the American Community Survey was used to examine changes in health insurance coverage for nonelderly adults, aged 26 to 64 years old, from 2013 to 2017. Using a differences-in-differences-in-differences (Triple-D) methodology, trends in insurance coverage were analyzed by different poverty levels. Medicaid expansion was treated as a policy variable with varying intensity since some states expanded in the middle of year (i.e. Louisiana, July 2016). Further, multivariate linear regression models were used to adjust for demographic and socioeconomic factors and standard errors were clustered by state. Lastly, person-weight was used to produce population estimates.

RESULTS

: Compared with the uninsured rates in 2013, the uninsured rates in 2017 decreased by 10.99%, 6.92% and 1.7% for people under 138% federal poverty level (FPL), between 138 – 400% FPL, and above 400% FPL, respectively. In all 5 years, populations with over 400% FPL continuously had the lowest uninsured rate, while populations with under 138% FPL had the highest uninsured rate. The uninsured rates decreased significantly after Medicaid expansion for all poverty levels. When comparing people <= 138% FPL with people > 138% FPL, the triple-D analysis found that there was a 4.75% reduction in uninsured risk after Medicaid expansion among populations under 138% FPL in Medicaid expansion states versus control states. After eliminating the impact of the ACA market exchange premium subsidy by comparing <=138% FPL vs. >400% FPL., 5.29% decrease was estimated due to expansion.

CONCLUSIONS

: Disparity in insurance coverage by poverty level significantly decreased among states with Medicaid expansion in the US. However, people under 138% FPL are still at a higher risk for being uninsured.