A wave of hospital closures in recent years has made it increasingly difficult for Missouri residents, particularly those in rural areas, to obtain health care. But a policy brief by researchers at the School of Public Health at Washington University in St. Louis shows that Missouri’s Medicaid expansion, implemented in 2021, may be helping some struggling hospitals stay open.
The study revealed that Medicaid expansion resulted in fewer hospital visits by uninsured patients and more by Medicaid-insured patients. While Medicaid reimbursement rates do not always cover the cost of care, hospitals often receive no compensation at all for the care they provide to uninsured patients, which undermines their financial stability.
“The Medicaid expansion is working as anticipated: More people are insured, which reduces the out-of-pocket costs for individuals and the uncompensated-care burden on hospitals,” said health policy expert Timothy McBride, MS, PhD, the Bernard Becker Professor at the School of Public Health and the lead investigator on the study. “What we didn’t anticipate is the magnitude of the effect. It appears to be a pretty darn big effect.
“Before Medicaid expansion passed, there were 10 or 12 hospitals in Missouri that closed their doors,” he continued. “Until recently, we haven’t had any hospitals close their doors. Medicaid expansion isn’t the only factor, but it’s a key indicator.”
For this policy brief, McBride and co-author Sarah Eisenstein, PhD, a statistical data analyst at the School of Public Health, analyzed emergency department visits and in-patient stays involving adults ages 19 to 64 at all hospitals in Missouri, from 2019 through 2024. During this time, two key events occurred related to Medicaid: the COVID-19 pandemic hit, leading Congress to temporarily forbid states from removing people from Medicaid; and Missouri voters passed Amendment 2 to the state constitution, expanding Medicaid eligibility under the Affordable Care Act.
From June 2021 through May 2023 — after Medicaid expansion began and while pandemic-era rules preventing disenrollment were still in effect — the number of adults on Medicaid in Missouri swelled by 350,000. At the same time, the proportion of emergency room encounters involving uninsured patients dropped by 10.6% and those involving Medicaid-insured patients rose by 13.8%, reducing the burden of uncompensated care on individuals and health systems. And rural areas benefited more than urban areas from the expansion. Rural residents are more likely to be uninsured than city dwellers, so rural hospitals routinely provide more uncompensated care and operate on thinner margins than urban hospitals.
After the public health emergency ended and states were once again allowed to disenroll people, Missouri removed more than 250,000 people from Medicaid. As a result, some of these trends reversed, but the overall amount of uncompensated care in the state remained lower than before Medicaid was expanded.
In addition to the policy brief, McBride and his team created two free, public, online dashboards so that researchers, policymakers, advocates, hospital administrators, health-care reporters and anyone else interested in how health care is paid for in Missouri can dive into the data themselves. One dashboard shows emergency department visits; the other, inpatient stays. The data are presented visually in charts, graphs and maps, and users can sort by patient age, region, kind of insurance, and rural or urban location. They will be updated quarterly.
Over the next few years, these dashboards may help reveal the effects of the most recent changes to Medicaid. Federal legislation signed into law in July includes more than $1 trillion in funding cuts and significant policy changes for Medicaid nationwide.
“We expect the bill to have big effects on Medicaid enrollment eventually, reversing many of the positive changes seen in Missouri recently,” McBride said. “It is projected, for example, that Missouri may lose over 120,000, and maybe as many as 160,000, from its Medicaid rolls eventually after all of the provisions of the big bill are implemented.”
McBride hopes to see more people take advantage of the dashboards and the dataset they are built on. While the dashboards are designed to provide answers related to how health care is paid for, the full dataset contains a wealth of detailed nonpartisan information that could be used to answer any number of health and health-care questions. The dataset underlying this work includes all emergency department visits and hospital admissions in Missouri going back to 2016, and includes information such as patient demographics, diagnoses and treatment for each encounter. Some analyses based on that information is forthcoming. All personally identifiable information such as names and birth dates has been removed, but individual patients have been assigned unique codes that would allow researchers to track them over time.
“We have a golden resource here,” McBride said. “The data use agreement allows us to aggregate the data and make it available to others, and that’s what we’re trying to do. Whatever your research question is — diabetes, heart disease, migraine, HIV — you can search through these data to look for patterns. We’re working to make this accessible to WashU faculty and students and even people outside of WashU, because there’s so much more we can learn about health and health care with a dataset like this.”
McBride TD, Eisenstein SA. Effects of the Medicaid Expansion and Unwinding on Hospital Encounters in Missouri, 2018-24. Center for Advancing Health Services, Policy and Economics Research. July 2025.
The development of the dashboards and the data analysis were supported by the Missouri Foundation for Health.
Writer
Tamara Schneider, MPH, PhD, is the senior science writer and assistant director of communications for WashU School of Public Health. She holds a bachelor’s degree in molecular biophysics & biochemistry and in sociology from Yale University, a master’s in public health from the University of California, Berkeley, and a PhD in biomedical science from the University of California, San Diego.