By Leah Frerichs, Ronny Bell, Kristen Hassmiller Lich, Daniel Reuland, and Donald Warne Regional Differences In Coverage Among American Indians And Alaska Natives Before And After The ACA ABSTRACT Understanding regional variation in the effect of the Affordable Care Act (ACA) on health insurance coverage among vulnerable populations such as American Indian and Alaska Native adults has important policy implications. We used American Community Survey data for the period 2010–17 to examine unadjusted trends in health insurance coverage among American Indians and Alaska Natives across ten US regions. In each region we also used multivariate regression to evaluate the effects of the ACA on insurance coverage among American Indians and Alaska Natives and differences in effects between that group and non-Hispanic whites. In the West we observed significant improvements in public insurance among American Indians and Alaska Natives, and disparities compared to non-Hispanic whites were reduced following the ACA. Although there were unadjusted increases in insurance coverage across most regions, regression analyses suggested that there were no significant post-ACA changes in public or private health insurance coverage among American Indians and Alaska Natives in the Oklahoma, Bemidji, or Alaska regions. In sum, health insurance among American Indians and Alaska Natives increased after the ACA, but improvements were not consistent across regions. More attention is needed to improve insurance coverage among American Indians and Alaska Natives in midwestern regions. H ealth disparities between Amer- ican Indians and Alaska Natives and non-Hispanic whites are well documented. 1,2 American Indians and Alaska Natives have some of the highest rates of poverty, illness, and death among racial/ethnic groups in the United States. 3,4 The factors that contribute to these health disparities are complex. Health care ac- cess among American Indians and Alaska Na- tives is one important factor that is largely mis- understood. Compared to non-Hispanic whites, American Indians and Alaska Natives are less likely to re- port having health care coverage or a provider. 5 There are many barriers to health insurance cov- erage for them, including low employment rates and low trust in health care institutions. 6,7 Prior estimates of uninsurance rates in this population have ranged between 18 percent and 35 percent, and differences by region have not been ex- plored. 8 Despite evidence of poor access, a com- mon misunderstanding persists that the Indian Health Service (IHS), the federally funded sys- tem of clinics and hospitals for American Indians and Alaska Natives, meets their health care needs and fills insurance coverage gaps. Howev- er, the majority of American Indians and Alaska Natives live in urban areas not served by the IHS. 9,10 Furthermore, the IHS is not a health in- doi: 10.1377/hlthaff.2019.00076 HEALTH AFFAIRS 38, NO. 9 (2019): 1542–1549 ©2019 Project HOPE— The People-to-People Health Foundation, Inc. Leah Frerichs (leahf@unc.edu) is an assistant professor of health policy and management at the Gillings School of Global Public Health, University of North Carolina at Chapel Hill (UNC-CH). Ronny Bell is a professor of public health at East Carolina University, in Greenville, North Carolina. Kristen Hassmiller Lich is an associate professor of health policy and management at the Gillings School of Global Public Health, UNC-CH. Daniel Reuland is a professor of medicine at the School of Medicine, UNC-CH. Donald Warne is director of the School of Medicine and Health Sciences, University of North Dakota, in Grand Forks. 1542 Health Affairs September 2019 38:9 Disparities Downloaded from HealthAffairs.org on September 05, 2019. Copyright Project HOPE—The People-to-People Health Foundation, Inc. For personal use only. All rights reserved. Reuse permissions at HealthAffairs.org.