Community Health Centers Maintained Initial Increases in Medicaid Covered Adult Patients at 5-Years Post-Medicaid-Expansion

Abstract

The Affordable Care Act (ACA) Medicaid expansion created new financial opportunities for community health centers (CHCs) providing primary care in medically-underserved communities. However, beyond evidence of initial policy effects, little is understood in the scholarly literature about whether the ACA Medicaid expansion affected longer-lasting changes in CHC patient insurance mix. This study's objective was to examine whether the ACA Medicaid expansion was associated with lasting increases in the annual percentage of adult CHC patients covered by Medicaid and decreases in the annual percentage of uninsured adult CHC patients at expansion-state CHCs, compared to non-expansion-state CHCs. This observational study examined 5353 CHC-year observations from 2012 to 2018 using Uniform Data System data and other national data sources. Using a 2-way fixed-effects multivariable regression approach and marginal analysis, intermediate-term policy effects of the Medicaid expansion on annual CHC patient coverage outcomes were estimated. By 5-years post-expansion, the Medicaid expansion was associated with an overall average increase of 11.7 percentage points in the percentage of adult patients with Medicaid coverage at expansion-state CHCs, compared to non-expansion-state CHCs. Among expansion-state CHCs, 39.8% of adult patients were predicted to have Medicaid coverage 5-years post-expansion, compared to 19.0% of non-expansion-state adult CHC patients. A state's decision to expand Medicaid was similarly associated with decreases in the annual percentage of uninsured adult CHC patients. Primary care operations at CHCs critically depend on patient Medicaid revenue. These findings suggest the ACA Medicaid expansion may provide longer-term financial security for expansion-state CHCs, which maintain increases in Medicaid-covered adult patients even 5-years post-expansion. However, these financial securities may be jeopardized should the ACA be ruled unconstitutional in 2021, a year after CHCs experienced new uncertainties caused by COVID-19.

Keywords: ACA; enrollment; health reform; primary care; uninsured.

Figure 1.

Unadjusted trends in the percentages of Medicaid-covered and uninsured adult CHC patients, by Medicaid expansion status: 2012 to 2018. Notes. This figure shows the unadjusted trends in the outcomes between the expansion-state CHCs (solid black line) and non-expansion-state CHCs (dashed black line) over the study period, allowing for a visual examination of the pre-expansion common trends assumption in the outcomes. The vertical dashed gray line at 2014 indicates the ACA Medicaid expansion in this study. Panel A shows the percentage of adult CHC patients with Medicaid coverage by Medicaid expansion status over time. Panel B shows the percentage of uninsured adult CHC patients by Medicaid expansion status over time.

Figure 2.

Predicted percentage of adult CHC patients with Medicaid coverage, by state Medicaid expansion status and time since expansion: 2012 to 2018. Notes. Author’s analysis of data from the Uniform Data System, Kaiser Family Foundation, and the Bureau of Labor Statistics. A ** indicated the difference in the average increase in the outcome from the pre-expansion period (2012-2013) to the post-expansion period (1-year or 5-years post-expansion) among the expansion-state CHCs minus the difference in the average increase in the outcome from the pre-expansion period (2012-2013) to the same post-expansion-period among the non-expansion-state CHCs was statistically significant, P < .01. The magnitude of these difference-in-differences estimates are equivalent to the “Expansion-state CHC at 1-year post-expansion” and “Expansion-state CHC at 5-years post-expansion” coefficients shown in Table 2.