Goldman, AnnaMcCormick, DannyHaas, JenniferSommers, Benjamin2018-06-202018Goldman, Anna L., Danny McCormick, Jennifer S. Haas, and Benjamin D. Sommers. 2018. “Effects Of The ACA’s Health Insurance Marketplaces On The Previously Uninsured: A Quasi-Experimental Analysis.” Health Affairs 37 (4) (April): 591–599. doi:10.1377/hlthaff.2017.1390.0278-2715http://nrs.harvard.edu/urn-3:HUL.InstRepos:37136775Descriptive studies have suggested that the Affordable Care Act’s (ACA) health insurance Marketplaces improved access to care. However, no quasi-experimental evidence is currently available to support these findings. We use longitudinal survey data to compare previously- uninsured adults to adults who had employer-sponsored insurance (ESI) prior to the ACA, in the income range eligible for subsidized Marketplace coverage (138-400% of poverty). Among the previously-uninsured group, the ACA led to a significant decline in the uninsurance rate (-10.8 percentage points), decreased barriers to medical care, increased use of outpatient services and prescriptions drugs, and increased identification of high blood pressure, compared to a control group with stable ESI. Changes were largest among those with incomes between 138-250% of poverty, who were eligible for the ACA’s cost-sharing reductions. Our quasi-experimental approach provides rigorous new evidence that the ACA’s Marketplaces led to improvements in several important health care outcomes, particularly among lower-income adults.en-USJournal Article2018-06-1720182018-06-2010.1377/hlthaff.2017.1390