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

Source: Danielle Rhubart, University of New Hampshire – Carsey School of Public Policy, National Issue Brief #111, Fall 2016

Key Findings:
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.

Counties and states with large shares of uninsured risk having to contend with a range of health and economic impacts, such as reduced workplace productivity, unsustainable demands on emergency departments, higher tax burdens resulting from uncompensated care costs, and deteriorating health care quality due to reductions in public spending.

In 2013, before the implementation of major provisions of the Affordable Care Act, 41 million U.S. adults age 19–64 had no health insurance. Coverage varies considerably by geographic location. For instance, in 2013 county-level coverage rates ranged from a high of 96 percent in Norfolk County, Massachusetts to a low of 57 percent in Willacy County, Texas.

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 (see Figure 1). 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. This research identifies differences in changes in insurance coverage rates for non-elderly adults (age 18–64) from 2013 to 2015 between counties in states that did and did not expand Medicaid. The analysis also identifies the county-level factors that contributed to these differences. The year 2013 is used as the starting point because Medicaid expansion did not begin until January 1, 2014.