Blog Center for Health Economics & Policy

Medicaid Expansion after one year; over 270,000 enrolled

Written by Timothy McBride, PhD, MS, Bernard Becker Professor at the Brown School and co-director of the Center for Health Economics & Policy at the Institute for Public Health


On October 1, 2022, Missouri reached a milestone, completing one year of Missouri Medicaid expansion. Although voters approved expansion to start July 1, 2021, enrollment began on October 1 due to litigation that was resolved by the Missouri Supreme Court. As of November 4, 2022, a total of 265,557 people were enrolled in the Adult Expansion Group (AEG) and 272,574 were enrolled by November 25. 

Under expansion, eligibility for the Medicaid program is expanded to the Adult Expansion Group (AEG): adults aged 19-64 earning up to 138% of the federal poverty line (FPL; $31,781 for a family of three.)

Figure 1: AEG enrollment over time

As shown in Figure 1, enrollment in the AEG has grown slowly over time, but accelerated in spring and summer 2022. After the conclusion of the lawsuit in the Missouri Supreme Court, the state of Missouri began accepting applications for Medicaid expansion in August 2021, and between August 2021 and September 2022, the state has received over 290,000 applications for expansion. 

Processing these applications proved difficult for the state when the number of “pending” applications grew rapidly, especially after November 2021, when the open enrollment period for the Affordable Care Act (ACA) began and the state received applications through the ACA portal.  A “mitigation plan” approved by the Center for Medicaid and Medicare Services helped lower the large number of pending applications.

In addition, enrollment grew slowly because a few populations already on the Medicaid program but now eligible for Medicaid under the expansion, were not added into the AEG for several months (until December 2021 and then April 2022), while these transitions happened more quickly in other states. 

Despite these challenges, it is notable that almost 300,000 people have applied for the Medicaid expansion in one year, and evidence suggests that many, if not most of these individuals, were uninsured before receiving the expansion coverage, and may never have had insurance before. The open enrollment period for the ACA began November 1, and may lead to another significant increase in the number of applications to Medicaid expansion. 


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