Study: Effects of Medicaid expansion grew in 2015

In the second year in which the Affordable Care Act was fully implemented, the law's expansion of Medicaid eligibility continued to reduce uninsured rates and improve coverage quality, according to new research.

In 2015, states that took advantage of the Affordable Care Act’s Medicaid expansion program saw greater declines in uninsured rates for low-income adults compared to states that declined to expand eligibility, according to a study published in Health Affairs. While uninsured rates fell in both expansion and nonexpansion states in 2014, the study found larger gains in Medicaid expansion states in 2015. Those gains significantly outstripped gains in nonexpansion states.

“The differential decline in the uninsurance rate in expansion states was mainly attributable to an increase in public coverage, as would be expected with expanded Medicaid eligibility,” according to the study. Notably, states that undertook Medicaid expansion did not see declines in rates of private coverage, which the authors say “suggests that new Medicaid eligibility did not lead people to drop private coverage to enroll in Medicaid.”

This study differs from previous studies, in that it uses higher-quality data gleaned from household interviews. This allowed researchers to drill down into coverage effects on subgroups. Men and childless adults saw the largest gains in coverage, which the study authors presume came about because those groups were less likely to be eligible for Medicaid coverage prior to expansion.

RELATED: Medicaid expansion slashed uninsured rates for poor, childless adults

More consequentially, the results demonstrate that low-income adults perceive an improvement in the quality of their insurance coverage. The study notes that this finding supports previous analyses showing consumer benefits generated by Medicaid expansion specifically, and the ACA more broadly, and indicates an upward trajectory for those benefits over time, growing in tandem with increased Medicaid enrollment.

Taken together, these results provide additional motivation for holdout states to revisit their position on Medicaid expansion, and for policymakers considering legislation to reform, replace or repeal the ACA, the study concludes.