News Center for Advancing Health Services, Policy & Economics Research

Center releases analysis of Medicaid expansion and the pandemic on hospital encounters in Missouri


An expansion of the Missouri Medicaid program was approved by voters in Missouri through the passage of a constitutional amendment in August 2020, and today the Center for Advancing Health Services, Policy and Economics Research released an initial analysis of the impacts of the expansion and the COVID-19 pandemic (through a public health emergency, PHE) on hospital encounters in Missouri.

The analysis is based on changes in hospital encounters over time in all hospitals in Missouri, before and after the start of the PHE and Medicaid expansion, concentrating on emergency department (ED) encounters and inpatient (IP) encounters, and the “payer mix” of those visits, which is the source of payment the hospitals receive (e.g., private, Medicaid, Medicaid, and uncompensated).

The findings suggest that in the period after the pandemic started, and later when the Medicaid expansion began (July 2021), the proportion of emergency department (ED) encounters financed by Medicaid rose by nearly 15 percentage points, while the proportion of encounters financed by the uninsured has dropped by 14 percentage points from January 2020 to December 2022. Similar trends were observed for inpatient encounters.

“These findings suggest that the expansion and growth in Medicaid enrollment in Missouri led to very large reductions in both the burden of uncompensated care for hospitals but also, importantly, out of pocket costs for previously uninsured persons in Missouri,” said Timothy McBride, the Bernard Becker Professor in the Brown School, and co-director of the Center for Advancing Health Services, Policy and Economic Research at the Institute for Public Health.

McBride points out that while the findings of a significant reduction in patients with hospital encounters that are uninsured is consistent with findings in other states that have expanded Medicaid, Missouri is relatively unique to have expanded Medicaid during the pandemic.

“Disentangling the part of the changes we are observing that are related to the rise in enrollment on Medicaid during the public health emergency from the expansion is a challenge, and will be a focus of future work,” McBride said.  “We also intend to look in detail at the implications for people with chronic conditions in Missouri, as compared to other states.”

The study also finds significant geographic variations in how the expansion of Medicaid and the PHE impacted regions of Missouri.  Before the pandemic started, a higher proportion of ED and inpatient encounters were funded by Medicaid in rural areas in Missouri, but the gap between urban and rural areas narrowed almost completely for ED encounters during the public health emergency.