The Impact of North Carolina Medicaid Expansion on Emergency Room Visits per County

##BACKGROUND North Carolina expanded Medicaid eligibility in December 2023 to adults aged 19–64 earning up to 138% of the federal poverty level. Existing evidence on how Medicaid expansion affects emergency department (ED) visits is mixed and largely heterogenous. This study evaluated the impact of Medicaid expansion on ED visit volume across all of North Carolina’s 100 counties. ##METHODS We conducted a county-level, pre-post analysis comparing ED visits from December 2022–November 2023 (pre-expansion) to January 2024–December 2024 (post-expansion), excluding December 2023 due to active enrollment. Using multivariate linear regression, the change in ED visits was modeled using 7 predictors including changes in Medicaid beneficiaries, population, hospital bed availability, urban-rural status, and access to Federally Qualified Health Centers (FQHCs) and Medication Assistance Program (MAP) sites. ##RESULTS The model explained 78% of the variation in ED visits (adjusted R² = 0.784) and 3 variables had statistically significant associations; population change demonstrated a positive association (standardized coefficient β = 0.756, P < .001), whereas changes in Medicaid beneficiaries (β = −2.27, P = .002) and hospital bed availability (β = −3.69, P < .001) were inversely associated. ##LIMITATIONS Study limitations include the use of county-level data, potential unmeasured confounders, and a relatively short 12-month follow-up period after Medicaid expansion. Longer follow-up may also be warranted to detect effects that were not statistically significant. Future research is needed to examine longer-term effects and determine other potential contributing factors. ##CONCLUSIONS Overall, our analysis suggests Medicaid expansion in North Carolina correlated with a reduction in ED visits one year after its enactment.