Paul Shafer is an assistant professor in the Department of Health Law, Policy, and Management at the Boston University School of Public Health and co-director of the Boston University Medicaid Policy Lab. His research focuses on the effects of state and federal health insurance policy on coverage, health care use and health equity. He is a member of the 2022 Tradeoffs Research Council.

We have amassed a lot of evidence on the benefits of Medicaid expansion — mortality, health and economic wellbeing, and equity all improve when more people have access to the program. But what about those who were already enrolled? Do they benefit from expansion too? A paper in the January issue of Health Affairs looks at that question through the lens of physician participation and the distance a patient has to travel to get care. 

Historically, fewer doctors accept Medicaid than Medicare or private insurance because of lower payment rates, and research has shown Medicaid expansion increased the number of doctors seeing Medicaid payments. That was the case in Louisiana, where researchers Dimitris Karletsos and Charles Stoecker attempted to figure out if existing beneficiaries in Louisiana were able to find more conveniently located doctors after the state expanded Medicaid in 2016. 

Karletsos and Stoecker used Medicaid claims data to measure the distance traveled from patients’ homes to different care providers before and after expansion. They found that travel distance decreased across the board. The decrease was steepest on average for trips to general practice (-3.46 miles) and primary care (-1.78 miles) doctors. The declines were even more pronounced among Black rural Medicaid enrollees, whose trips were on average nearly 10 miles shorter for general practice and 3 miles shorter for primary care after expansion. Even in metropolitan areas, Black Medicaid enrollees had significantly shorter travel distances to all eight provider types included in their study.

One limitation to this study is the authors didn’t necessarily have the current address for each enrollee — just the most recent one provided — and this can be a problem with Medicaid enrollees who tend to move around. Also, the same distance can be a very different burden in metropolitan versus rural areas, so it would be interesting to see how their results would change using driving and transit time instead of distance.

But the findings are incredibly encouraging. We know that having to travel long distances to see a doctor hurts people’s health — especially people living in rural areas and racial and ethnic minorities. This paper shows that expanding Medicaid in Louisiana helped shorten those distances and reduce some of these disparities. As one of the few states in the South to expand Medicaid, Louisiana shows how expansion can improve access for those newly eligible for coverage and those already in the program.