Premium subsidies, the mandate, and Medicaid expansion: Coverage effects of the Affordable Care Act

Abstract

Using premium subsidies for private coverage, an individual mandate, and Medicaid expansion, the Affordable Care Act (ACA) has increased insurance coverage. We provide the first comprehensive assessment of these provisions' effects, using the 2012-2015 American Community Survey and a triple-difference estimation strategy that exploits variation by income, geography, and time. Overall, our model explains 60% of the coverage gains in 2014-2015. We find that coverage was moderately responsive to price subsidies, with larger gains in state-based insurance exchanges than the federal exchange. The individual mandate's exemptions and penalties had little impact on coverage rates. The law increased Medicaid among individuals gaining eligibility under the ACA and among previously-eligible populations ("woodwork effect") even in non-expansion states, with no resulting reductions in private insurance. Overall, exchange premium subsidies produced 40% of the coverage gains explained by our ACA policy measures, and Medicaid the other 60%, of which 1/2 occurred among previously-eligible individuals. Americans to obtain insurance (with several exemptions, most notably related to affordability). KeywordsThese principal pieces of the ACA took effect in January 2014. 1 National data from multiple sources strongly support the notion that the ACA has reduced the uninsurance rate substantially beginning in 2014, reaching an historic low by 2015 (Cohen & Martinez, 2014;Smith & Medalia, 2015;Sommers, Gunja, Finegold, & Musco, 2015). This drop has generally been attributed to the ACA, but most analyses of the ACA to date have 1 The earliest coverage expansion enacted under the ACA was the dependent coverage provision, which mandated that private insurers allow parents to cover their children on their insurance until age 26. This provision took effect September 2010. We do not examine this policy here, since it had essentially reached steady-state by 2012 and has already been examined thoroughly elsewhere (Antwi, Moriya, & Simon, 2013). 4 been largely descriptive (Cohen & Martinez, 2014;Long et al., 2014) or limited to a particular aspect of the ACA such as the Medicaid expansion (Black & Cohen, 2015;Kaestner, Garrett, Gangopadhyaya, & Fleming, 2015;Wherry & Miller, 2016). No studies have disentangled the different coverage effects of the ACA's various provisions. Even as the 2016 election results cast uncertainty over the ACA's future, these issues remain critically important to understanding the potential impact of a partial or complete rollback of the law, as well as the potential consequences of future state or federal efforts to expand coverage.In this paper, we provide the first comprehensive model that identifies the causal impact of the ACA's numerous provisions on insurance coverage. In doing so, we also offer an empirical template for future research on this wide-ranging law. We use data from the American Community Survey (ACS) for the two years before and two years after full ACA implementation. We estimate rich mod...

Veterans' Health Insurance Coverage Under the Affordable Care Act and Implications of Repeal for the Department of Veterans Affairs

“…The adjusted probability of being uninsured fell by 12 percentage points for newly eligible nonelderly veterans and by 7.7 percentage points for previously eligible veterans. The decline in uninsurance was statistically significantly larger for newly eligible veterans, a pattern similar to that documented by Frean, Gruber, and Sommers (2017) for the overall population under age 65. 5 We also found a smaller, but significant, decline in uninsurance (-3.4 percentage points) and an increase in Medicaid coverage (4.7 percentage points) for the previously eligible population in nonexpansion states.…”

“…To encourage take-up, the ACA contained many measures intended to facilitate Medicaid enrollment, and additional factors, such as the publicity surrounding ACA implementation and the individual mandate, may also have served to increase Medicaid enrollment among previously eligible adults in both expansion and nonexpansion states. For the general adult population, roughly half of the gains in coverage due to Medicaid occurred among previously eligible adults, with the other half attributable to expanded eligibility (Frean, Gruber, and Sommers, 2017). A rollback of Medicaid expansion would, by definition, reduce Medicaid coverage for newly eligible veterans but may not have direct impacts on the previously eligible, newly enrolled population.…”

Disentangling the ACA’s Coverage Effects — Lessons for Policymakers

“…Our preliminary analysis identified several key results with policy implications. 2 We find that the biggest factor in the coverage expansion in 2014 was Medicaid, which produced 63% of the gains we identified. This effect, however, actually comprised several distinct phenomena.…”

“…There is a clear and logical "ethical and scientific imperative" 1 for doing so, to permit activities ranging from verification of the original analysis to testing of new hypotheses. This interest has resulted in many publications and meetings, attention from the Institute of Medicine, 2 proposed changes in journals' policies, 3 and enormous effort from pharmaceutical sponsors and other groups to provide access to patient-level data. 4 It is critical that we learn from these early experiences as we move forward.…”

Delivering Public Health Insurance Through Private Plan Choice in the United States

“…Over time, as some states have stopped providing their own exchanges, enrollment in stateadministered exchanges has stagnated at 2.8 million while enrollment in the federally run exchange has risen to 8.7 million. The differences between stateand federally-administered exchanges are not obvious to the enrollee, but Frean, Gruber, and Sommers (2017) find that enrollment grew much faster, and consumers were more responsive to subsidies, in state-administered exchanges (perhaps due to other correlated state outreach programs).…”