QuickTake: Taking Stock: Health Insurance Coverage under the ACA as of December 2014


Sharon K. Long, Michael Karpman, Genevieve M. Kenney, Douglas Wissoker, Nathaniel Anderson and Stephen Zuckerman

March 12, 2015


Following the implementation of the Affordable Care Act’s (ACA) key coverage expansions, including the availability of subsidized coverage through new health insurance Marketplaces and the state option to expand Medicaid to nearly all adults with family income at or below 138 percent of the federal poverty level (FPL), federal and nonfederal surveys have shown a sharp decline in the share of nonelderly adults who are uninsured (Carman and Eibner 2014; Collins et al. 2014; Long et al. 2014; Martinez and Cohen 2014).1 This QuickTake draws on data from the Urban Institute’s Health Reform Monitoring Survey (HRMS) to provide estimates of coverage changes through early December 2014, when the most recent round of the HRMS was fielded. The December wave occurred just after the start of the second Marketplace open enrollment period.2 We focus on changes in coverage between September 20133 and December 2014 for nonelderly adults, overall and by state Medicaid expansion status.4 We also report coverage changes for the overall nonelderly adult population and in Medicaid expansion and nonexpansion states by family income, age, race and ethnicity, and gender.


What We Found


The uninsurance rate for nonelderly adults fell from 17.7 percent to 12.8 percent between September 2013 and December 2014.


From just before the initial open enrollment period in September 2013 to the first few weeks of the second open enrollment period in December 2014, the uninsurance rate for nonelderly adults fell from 17.7 percent to 12.8 percent, a drop of 27.5 percent (figure 1). Applying the 4.9 percentage-point (95% CI [3.5, 6.2]) decrease in the uninsurance rate to the estimated national population of nonelderly adults yields a net coverage gain of 9.7 million (95% CI [7.0 million, 12.3 million]) adults during this period.5 Although the estimate of the uninsurance rate for December 2014 is slightly lower than that for September 2014, the difference between the two estimates is not significantly different from zero.


There are more substantial differences between September 2014 and December 2014 in the estimates of the uninsurance rates for adults in states that did not expand Medicaid. The uninsurance estimate for the nonexpansion states in September 2014, although quite robust to several sensitivity tests (Long et al. 2014), appears to be a statistical aberration: the most recent quarter of data shows a more moderate coverage gain that is more consistent with earlier trends. Additional quarters of data will provide a better indication of the trend in coverage for these states.



The uninsurance rate for states that expanded Medicaid by December 2014 dropped from 16.2 percent to 10.0 percent, a decline of 38.3 percent (figure 1). In contrast, the uninsurance rate for states that did not expand Medicaid fell from 19.6 percent to 16.3 percent, a decline of 16.9 percent. Although 45 percent of nonelderly adults live in nonexpansion states, those states were home to a disproportionate share of adults who were uninsured in December 2014 (56.6 percent; data not shown).


Coverage gains have been strongest for low- and middle-income adults targeted by key ACA provisions.


Low- and middle-income adults targeted by the Medicaid expansion and Marketplace subsidies (those with family income at or below 138 percent of FPL and those with family incomes between 139 and 399 percent of FPL, respectively) experienced the largest coverage gains. Coverage for low-income adults rose 10.0 percentage points (95% CI [6.5, 13.6]) between September 2013 and December 2014 (figure 2). The share of middle-income adults with insurance rose 5.5 percentage points (95% CI [3.6, 7.5]) during this period. There was no statistically significant change in coverage for higher-income adults with family incomes at or above 400 percent of FPL.



Though young adults and racial and ethnic minorities had the largest percentage-point gains in insurance coverage, gains occurred for adults in all age, gender, and racial and ethnic groups.


Coverage for adults ages 18 to 30 increased 6.3 percentage points (95% CI [3.0, 9.5]), compared with 4.2 percentage points (95% CI [2.0, 6.4]) for adults ages 31 to 49 and 4.7 percentage points (95% CI [3.0, 6.5]) for adults ages 50 to 64.


Among racial and ethnic groups, Hispanic adults had the largest percentage-point increase in coverage (9.4 percentage points; 95% CI [7.2, 11.7]), followed by nonwhite, non-Hispanic adults (5.2 percentage points; 95% CI [1.9, 8.5]) and white, non-Hispanic adults (3.4 percentage points; 95% CI [2.1, 4.8]). Coverage gains were similar for men (5.0 percentage points; 95% CI [3.2, 6.8]) and women (4.6 percentage points; 95% CI [2.9, 6.3]).


The gains in insurance coverage for low-income adults continue to be larger in states that expanded Medicaid than in states that did not.


As shown in figure 3, the share of low-income adults with insurance coverage rose 14.8 percentage points in expansion states (95% CI [10.1, 19.5]) and 4.6 percentage points in nonexpansion states, although the latter was not statistically significant (95% CI [-0.2, 9.5]). Middle-income adults who may be eligible for subsidized coverage through the Marketplaces experienced similar percentage-point reductions in uninsurance in states that did and did not expand Medicaid. In addition, coverage rates were stable for higher-income adults in both state groups.


Coverage gains were also larger in expansion states for young adults and nonwhite, non-Hispanic adults.


In expansion states, coverage increased 9.0 percentage points (95% CI [6.5, 11.5]) for adults ages 18 to 30 and 8.2 percentage points (95% CI [5.6, 10.8]) for nonwhite, non-Hispanic adults. Coverage gains for these groups in nonexpansion states were smaller and not statistically significant.



What It Means


We find that the number of adults without insurance coverage fell 9.7 million from just before the first open enrollment period through early December 2014, with large coverage gains in states that expanded Medicaid and among the low-income nonelderly adults targeted by the Medicaid expansion. Not all of these gains can necessarily be attributed to the ACA provisions related to eligibility for Medicaid and subsidized coverage, because other factors may account for changes in insurance coverage, including the improving economy and differences in federal funding for outreach and enrollment assistance between states that operate their own Marketplaces and states that use the federal Marketplace.


Continued implementation of ACA provisions may further lower the uninsurance rate for nonelderly adults by the time the next round of the HRMS is fielded in March 2015. As of February 15, 2015, 8.6 million individuals had selected or been reenrolled in a health plan through the federal Marketplace platform, and about 2.8 million had done so through state Marketplace platforms.6 Plan selections in the federal Marketplace increased to over 8.8 million by February 22 following a special enrollment period (SEP) for people who had started applications but experienced technical issues or waited in line at the call center.7


In addition, more uninsured may enroll during the SEPs that were announced in late February for all states using the federal Marketplace platform and most states using their own Marketplace platforms.8 The new SEPs are targeted at uninsured individuals who are learning that they owe a tax penalty for being uninsured in 2014 when they prepare their taxes and could face an even bigger penalty in 2016. HRMS data show that as of December 2014, just over half (53.5 percent) of uninsured adults with incomes above 100 percent of FPL reported hearing “some” or “a lot” about the penalty (Karpman et al. 2015).


Additional Medicaid enrollment is also likely because Pennsylvania and Indiana have expanded Medicaid since the December HRMS survey. In addition, as of January 1, 2015, employers with more than 100 employees will face penalties if they do not provide coverage to their workers and at least one full-time employee receives subsidized coverage through the Marketplace.9 Finally, factors other than the ACA, such as continued job growth10 and resulting increases in employer-sponsored coverage, may also increase the share of adults with insurance going forward.


Methods: Each round of the HRMS is weighted to be nationally representative. We use these weights and a regression adjustment11 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., quarters 1–4 of 2014). We focus on statistically significant changes in insurance coverage over time (defined as changes 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.




Assistant Secretary for Planning and Evaluation. 2014. Health Insurance Marketplace 2015 Open Enrollment Period: December Enrollment Report. Washington, DC: US Department of Health and Human Services.


Carman, Katherine Grace, and Christine Eibner. 2014. Changes in Health Insurance Enrollment since 2013. Santa Monica, CA: RAND Corporation.


Collins, Sara R., Petra W. Rasmussen, and Michelle M. Doty. 2014. Gaining Ground: Americans' Health Insurance Coverage and Access to Care after the Affordable Care Act's First Open Enrollment Period. New York: Commonwealth Fund.


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.


Karpman, Michael, Genevieve M. Kenney, Sharon K. Long, and Stephen Zuckerman. 2015. QuickTake: As of December, Many Uninsured Adults Were Not Aware of Tax Penalties for Not Having Coverage, the Marketplaces, or the Open Enrollment Deadline. Washington, DC: Urban Institute.


Martinez, Michael E., and Robin A. Cohen. 2014. Health Insurance Coverage: Early Release of Estimates from the National Health Interview Survey, January–June 2014. Hyattsville, MD: National Center for Health Statistics.


About the Series


This QuickTake is part of a series drawing on the HRMS, a quarterly survey of the nonelderly population that is exploring the value of cutting-edge Internet-based survey methods to monitor the ACA before data from federal government surveys are available. The QuickTakes provide information on health insurance coverage, access to and use of health care, health care affordability, and self-reported health status, as well as timely data on important implementation issues under the ACA. Funding for the core HRMS is provided by the Robert Wood Johnson Foundation and the Urban Institute.


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



1 Jenna Levy, “In U.S., Uninsured Rate Sinks to 12.9%,”  Gallup. January 7, 2015.

2 The second Marketplace open enrollment period began November 15, 2014, and ended February 15, 2015. The field period for the December 2014 HRMS was December 2 through December 29, 2014. More than half of respondents completed the survey in the first week of December and over 90 percent completed the survey by the end of the second week. Marketplace data show that as of December 15, 2014, just over 4 million people had selected or been reenrolled in a plan sold in state or federal Marketplaces (Assistant Secretary for Planning and Evaluation 2014). By February 15, 2015, 11.4 million had selected a plan or had been reenrolled in a plan through the Marketplace (See US Department of Health and Human Services, “Open Enrollment Week 13: February 7, 2015 – February 15, 2015,” HHS.gov Facts & Features Blog, February 18, 2015). Additional plan selections were made during a special open enrollment period for people who started applications but experienced technical issues or waited in line at the call center (See US Department of Health and Human Services. “Open Enrollment Week 14: February 16, 2015 – February 22, 2015,” HHS.gov Facts & Features Blog, February 25, 2015). Therefore, our December estimates do not reflect the bulk of recent coverage gains that may have resulted from increasing enrollment through the state and federal Marketplaces. Furthermore, with the extension of a special enrollment period (from March 15, 2015, to April 30, 2015) to individuals subject to the tax penalty for not having coverage in states using the federal Marketplace, and with similar special enrollment periods in some states operating their own Marketplaces, additional gains in coverage are possible.

3 Although Marketplace coverage for people enrolling between October 2013 and December 2013 did not start until January 2014, some who signed up in the fall may have reported having coverage during the December 2013 HRMS survey. Further, some of those seeking coverage through the Marketplace between October 2013 and December 2013 were enrolled in Medicaid.

4 For this analysis, we focus on state decisions to expand Medicaid by December 1, 2014. The states that expanded Medicaid by this date are AZ, AR, CA, CO, CT, DE, DC, HI, IL, IA, KY, MD, MA, MI, MN, NH, NV, NJ, NM, NY, ND, OH, OR, RI, VT, WA, and WV. Several of those states, including CA, CT, DC, and MN, expanded Medicaid under the ACA before 2013.

5 To extrapolate our estimates of changes in uninsurance rates to the number of adults who have gained coverage over the same period, we use projections for the size of the 2014 population from the US Census Bureau. These files give population projections by race, ethnicity, and sex of all ages from 2014 to 2060 based on estimated birth rates, death rates, and net migration rates. Using the “Table 1” file (which has a 2014 projected population of 318,748,017), we summed the 2014 population projections for all 18-to-64-year-olds to arrive at 198,902,067 nonelderly adults in 2014. See US Census Bureau, “2014 National Population Projections: Downloadable Files,” US Department of Commerce, last modified December 10, 2014.

6 US Department of Health and Human Services. “Open Enrollment Week 13: February 7, 2015 – February 15, 2015.”

7 US Department of Health and Human Services. “Open Enrollment Week 14: February 16, 2015 – February 22, 2015.”

8 “Tax Season Special Enrollment Periods,”  Manatt Health Solutions, last modified February 25, 2015.

9 “Employer Responsibility Under the Affordable Care Act,” Kaiser Family Foundation, last modified December 17, 2014.

10 Bureau of Labor Statistics, “The Employment Situation – January 2015,” news release,  February 6, 2015.

11 Specifically, we control for the variables used in the poststratification weighting of the KnowledgePanel (the internet-based survey panel that underlies the HRMS) and the poststratification weighting of the HRMS. These variables are sex, age, race and ethnicity, language, education, marital status, whether any children are present in the household, household income, family income as a percentage of FPL, homeownership status, Internet access, urban or rural status, and census region. In this analysis, we also control for citizenship status and participation in the previous quarter’s survey (i.e., whether the responded completed survey in the previous quarter, was sampled in the previous quarter but did not complete survey, or was not sampled in the previous quarter).



Urban Institute Robert Wood Johnson Foundation