Medicaid Expansion Under ACA Led to Increased Insurance Coverage, Less Financial Worry, Longer Wait Times for the Poor


Professor Sarah Miller examines effects of Medicaid expansion in research published in the New England Journal of Medicine.

States that participated in Medicaid expansion under the Affordable Healthcare Act saw increased insurance coverage and access to care, less worry about paying medical bills, but also longer wait times among low-income residents, according to new research.

In an article in the latest edition of the New England Journal of Medicine, Professors Sarah Miller of Michigan Ross and Laura R. Wherry of the David Geffen School of Medicine at UCLA analyze survey data from states that participated in the Medicare expansion and states that declined.

The study comes as Congress debates a proposed replacement of the Affordable Care Act.


The authors found uninsurance rates dropped in the expansion states in year two by 8.2 percentage points and Medicaid coverage increased 15.6 percentage points among low-income residents when compared with non-expansion states.

Though expansion wasn’t associated with significant changes in health status, expansion states saw an increase in the ability to afford follow-up care for low-income residents — 3.4 percentage points compared with non-expansion states — and fewer reports of worry about paying medical bills — a decrease of 7.9 percentage points compared with non-expansion states.

“These results suggest that any proposed cuts to the ACA Medicaid expansions would substantially reduce access to health care for low-income individuals,” said Miller.

Miller and Wherry also found expansion states reported increases in medical care delays due to wait times for low-income residents, a 2.6 percentage-point increase over non-expansion states.

“This may have resulted from additional strain on medical providers to absorb new demand for medical care, or may reflect provider reluctance to accept Medicaid patients because of low reimbursement rates,” they write in the article.

Miller and Wherry compared changes in outcomes two years after the Medicaid expansion — 2014 and 2015 — relative to the four years before it. They used data from the National Health Interview Survey and compared results from the expansion and non-expansion states. The survey sample was 60,766 U.S. citizens between 19-64 years of age who had incomes below 138 percent of the federal poverty level.

By September 2015, a total of 29 states and Washington, D.C., participated in the Medicaid expansion.



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