QuickTake: Uninsurance Rate Down 25 Percent for Working Adults and 31 Percent for Low-Income Workers since September 2013


Michael Karpman

February 4, 2015


The Urban Institute is using the Health Reform Monitoring Survey (HRMS) to examine trends in health insurance coverage and other health and economic outcomes for adults and their families under the Affordable Care Act (ACA). Recent HRMS data show an estimated 10.6 million adults ages 18 to 64 gained coverage between September 2013, just before the first open enrollment period for the ACA’s health insurance Marketplaces, and September 2014, just before the second open enrollment period (Long et al. 2014). This QuickTake extends that work to examine trends in coverage for working adults overall and by family income, parental status, and state Medicaid expansion status. We find the largest coverage gains for low-income workers.


Between September 2013 and September 2014, the uninsurance rate fell 3.4 percentage points (95% CI [2.0, 4.9]; figure 1) for working nonelderly adults. The share of working nonelderly adults without insurance declined from an estimated 13.6 percent just before the first open enrollment period to 10.2 percent in September 2014, a 25.3 percent decline. Though the gap in the uninsurance rate between working and nonworking adults narrowed over this period, nonworking adults remained 6.2 percentage points more likely to be uninsured compared with employed adults (data not shown).



Working adults targeted by the ACA’s Medicaid expansion saw the largest coverage gains. The uninsurance rate for low-income workers targeted by the ACA’s Medicaid expansion (those with family income at or below 138 percent of the federal poverty level) fell 13.4 percentage points (95% CI [8.8, 18.1]; figure 2) from 43.5 percent in September 2013 to 30.1 percent in September 2014 (data not shown), a 30.9 percent reduction. Workers targeted by subsidies for coverage purchased through the health insurance Marketplace (those with family income between 139 and 399 percent of the federal poverty level) experienced a smaller uninsurance rate reduction of 2.6 percentage points (95% CI [0.7, 4.6]). Workers with higher incomes did not experience a statistically significant change in their uninsurance rate.



Workers in states that expanded Medicaid by September 2014 also had stronger coverage gains (4.1 percentage points; 95% CI [2.2, 6.0]) than workers in states that did not expand Medicaid (2.6 percentage points; 95% CI [0.5, 4.7]; figures 1 and 2). The uninsurance rate for working adults in September 2014 was 12.5 percent in nonexpansion states and 8.4 percent in expansion states.


Coverage gains were shared equally among working parents1 and workers without children in the household. The uninsurance rate fell 3.4 percentage points (95% CI [1.3, 5.4]) for working parents and 3.3 percentage points for working adults without children in the household (95% CI [1.6, 5.1]; figure 2).


Methods: Each round of the HRMS is weighted to be nationally representative. We use these weights and a regression adjustment to control for differences in the demographic and socioeconomic characteristics of the respondents across the different rounds of the survey. This allows us to remove any variation in insurance coverage caused by changes in the types of people responding to the survey over time rather than by changes in the health insurance landscape. The basic patterns shown for the regression-adjusted measures are similar to those based solely on simple weighted estimates. In presenting the regression-adjusted estimates, we use the predicted rate of each coverage type in each quarter for the same nationally representative population. For this analysis, we base the nationally representative sample on survey respondents from the most recent 12-month period from the HRMS (i.e., quarter 4 of 2013 and quarters 1?3 of 2014). We focus on statistically significant changes in insurance coverage over time (defined as differences that are significantly different from zero at the 5 percent level or lower) and highlight changes relative to September 2013, just before the open enrollment period for the Marketplaces began. We provide a 95 percent confidence interval for key estimates.


Limitations to the analysis: The HRMS is designed to provide early feedback on ACA implementation to complement the more robust assessments that will be possible as more federal survey data become available. Though HRMS estimates capture the changes in insurance coverage from the first open enrollment period under the ACA, the estimates understate the full effects of the ACA because the estimates do not reflect the effects of some important ACA provisions (such as the ability to keep dependents on health plans until age 26 and early state Medicaid expansions) that were implemented before 2013. In addition, these change estimates might not reflect only the effects of the ACA, because they do not control for long-term trends in health insurance coverage that predate the ACA nor do they control for changes in the business cycle. Further, the difference in coverage gains between the states that did and did not expand Medicaid should not be entirely attributed to the ACA; there were other policy choices that likely affected enrollment. For example, many of the nonexpansion states did not set up their own Marketplaces and therefore did not get the same access to outreach and enrollment assistance funding.




Long, Sharon K., Michael Karpman, Adele Shartzer, Douglas Wissoker, Genevieve M. Kenney, Stephen Zuckerman, Nathaniel Anderson, and Katherine Hempstead. 2014. “Taking Stock: Health Insurance Coverage under the ACA as of September 2014.” Washington, DC: Urban Institute.


About the Series


This QuickTake is part of a series drawing on the HRMS, a quarterly survey of the nonelderly population that explores the value of cutting-edge Internet-based survey methods to monitor the Affordable Care Act before data from federal government surveys are available. Funding for the core HRMS is provided by the Robert Wood Johnson Foundation and the Urban Institute, and this analysis was also supported by funding from the Ford Foundation.


For more information on the HRMS and for other QuickTakes in this series, visit www.urban.org/hrms.



1 Our definition of parents includes adults who are guardians of children in their household.

Urban Institute Robert Wood Johnson Foundation