Medicaid Expansion Fueled ED Visits, but More Patients Had Insurance, Study Finds

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Experts hoped that Medicaid expansion would direct the previously uninsured into primary care and reduce reliance on the emergency department. What happened is more complicated.

Visits to the emergency department (ED) rose in states that expanded Medicaid under the Affordable Care Act (ACA) in 2014, according to a study published Monday that confirms earlier surveys of emergency physicians.

Even though patients didn’t shift to primary care as quickly as experts hoped, the study had some good news—fewer patients who showed up in the ED in expansion states were uninsured.

The study, led by Sayeh Nikpay, PhD, MPH, of Vanderbilt University, and reported at the meeting of the American College of Emergency Physicians, found that ED use increased by 2.5 visits per 1000 population in 14 Medicaid expansion states in 2014, compared with 11 nonexpansion states. Compared with nonexpansion states, the share of ED visits covered by Medicaid rose 8.8 percentage points, and the share not covered by insurance decreased by 5.3 percentage points.1

The study, published in the Annals of Emergency Medicine, is drawn from data published by the Agency for Healthcare Research and Quality (AHRQ) and runs counter to what experts predicted, even though it reflects what ED physicians have reported.


“Medicaid expansion had a larger impact on the healthcare system in places where more people were expected to gain coverage,” Nikpay said in a statement. “The change in total visits was twice as large in a state like Kentucky, where most childless adults were ineligible for Medicaid at any income level before 2014, than in states like Hawaii, where childless adults were already eligible for Medicaid above the poverty line.”

The study dug into the data to note that increases were largest for “injury-related” visits and greatest in states where the benefits were leanest prior to expansion. In an accompanying editorial, author Ari B. Friedman, MD, PhD, attempted to make sense of the findings in light of earlier studies that used different methods, but all reached the same finding: “Medicaid expansion did not decrease and may have increased ED visits.”2

But is this a failure of the health system? Friedman wrote that one must look at the costs of the ED visits and what the patients’ alternatives were, saying that the increase in visits “is neither clearly bad nor clearly good.”

It’s been documented that some newly covered Medicaid beneficiaries have found it’s not that easy to connect with a primary care physician, and insurers and health systems are working to correct this. But another issue is that people who went most of their lives without coverage keep going to the ED because it’s what they know. Health systems must retrain patients to use primary care. In New Orleans, for example, Daughters of Charity Health System can find out if one of its patients checks into the ED with a non-urgent condition and redirect the person to a clinic.

Friedman wrote that for the time being, the view toward emergency care needs to be more flexible.

“We need to move beyond the value judgments that have dominated so much of emergency department utilization towards a more rational basis for how we structure unscheduled visits in the health system,” Friedman wrote.


1. Nikpay S, Freedman S, Levy H, Buchmueller T. Effect of the Affordable Care Act Medicaid expansion on emergency department visits: evidence from state-level emergency department databases [published online June 19, 2017]. Ann Emerg Med. 2017; DOI:

2. Friedman AB. The uncertain economics of insurance enabling more emergency department visits [published June 19, 2017]. Ann Emerg Med. 2017; DOI: