The Impact of State Medicaid Expansion Under the Affordable Care Act on Health Insurance Coverage at the County Level

The purpose of Medicaid expansion under the Affordable Care Act was to make health care more accessible to low-income populations. By early 2015, 28 states had expanded Medicaid eligibility. The expansion by some states but not by others provides a unique opportunity to examine the impact of this new policy on changes in health insurance coverage. Moreover, as the newly elected Republican President and the Republican-controlled Congress consider the future of health care reform, understanding the efficacy of components of the Affordable Care Act, such as Medicaid expansion, will be essential for continuing efforts to increase coverage rates and subsequently minimize the associated consequences of low coverage rates. In this brief, author Danielle Rhubart reports that counties in states that did not expand Medicaid compared to counties in states that did experienced significantly smaller increases in non-elderly adult health insurance coverage between 2013 and 2015, even after controlling for other county characteristics. Counties in states that did not expand Medicaid compared to counties in states that did had larger shares of the vulnerable populations. Within states that did not expand Medicaid, counties with larger shares of vulnerable residents experienced smaller improvements in health insurance coverage rates than did counties with smaller shares of vulnerable residents. She concludes that any proposed revisions to the ACA, and especially the curtailment of Medicaid, would reduce county-level insurance coverage rates and thus require counties to find new ways to deal with an increase in uninsured non-elderly adults. For counties with large shares of vulnerable populations located in states that did not expand Medicaid, leaders interested in reducing the impact of lack of health insurance coverage should focus on increasing access to low-cost health care and preventive health