The Impact of Insurance Expansions on the Already Insured: The Affordable Care Act and Medicare

Abstract

Some states have not adopted the Affordable Care Act (ACA) Medicaid expansions due to concerns that the expansions may impair access to care and utilization for those who are already insured. We investigate such negative spillovers using a large panel of Medicare beneficiaries. Across many subgroups and outcomes, we find no evidence that the expansions reduced utilization among Medicare beneficiaries and can rule out all but very small changes in utilization or spending. These results indicate that the expansions in Medicaid did not impair access to care or utilization for the Medicare population. (JEL G22, H51, I13, I18, I38)

Medicaid Expansion Spillover Effects on Health Care Consumption and Coverage: Evidence from Medicare Administrative Data

“…For total spending in column 2, we obtain a point estimate of $99.4 and a 95 percent confidence interval that rules out negative spillovers of larger than $269 per enrollee, or about 4.5 percent of baseline spending of $5,967. 12 This result is consistent with the most similar estimate in the literature, provided by Carey, Miller, and Wherry (2020).…”

“…Our paper plays a unique role in this literature, providing a possible reconciliation for findings that, on the surface, seem to disagree. By splitting our sample by birth cohort, we find evidence consistent with Carey, Miller, and Wherry (2020), Joynt et al (2013), andJoynt et al (2015) that there was no crowd out of access from these recent health care reforms, while also obtaining negative spending effects like Bond and White (2013), Hong (2018), andMcInerney, Mellor, andSabik (2017) among our younger cohort. Moreover, our finding of heterogeneity by cohort provides an alternative explanation for spending reductions to that given by Hong (2018) andMcInerney, Mellor, andSabik (2017).…”

“…One common concern has been the following question: "If an expansion results in more people trying to access health care services, would access to care for Medicare beneficiaries be reduced?" While several sets of authors have studied this question, previous research has produced conflicting answers (Joynt et al 2013;Bond and White 2013;Joynt et al 2015;McInerney, Mellor, and Sabik 2017;Glied and Hong 2018;Carey, Miller, and Wherry 2020). In this paper, we consider these indirect effects and the ACA Medicaid expansion, performing a comprehensive evaluation of its spillovers into the Medicare population, studying effects on dual enrollment, Medicare spending, and health conditions.…”

Did the ACA Medicaid Expansion Save Lives?

“…This assumption would be violated, for example, if there were responses among those who switched onto Medicaid from other sources of insurance, or if the benefits of health insurance affect households or communities. A growing literature documents responses consistent with diffuse benefits of Medicaid on, for example, financial outcomes (Hu et al (2016), crime (Vogler (2017), He (2018)), and hospital closures (Lindrooth et al (2018)); there is also little evidence of negative spillovers through congestion effects (Carey, Miller and Wherry (2018)). Large TOT estimates appear to be a feature of public insurance studies, suggesting that assessment of these programs should allow for benefits in the general population, and future research should more closely ex-amine the sources of gains from health insurance.…”

Medicaid Expansion Spillover Effects on Health Care Consumption and Coverage: Evidence from Medicare Administrative Data

“…Both studies, however, present suggestive evidence that the spending crowded out in these cases was low-value care. In a study more closely related to ours, Carey, Miller, and Wherry (2020) examine the impact of the ACA Medicaid expansion on primary care access and overall spending in Medicare for post-65 beneficiaries, estimating precise zero effects using administrative claims data.…”