Medicaid Expansion and Not-For-Profit Hospitals' Financial Status: National and State-Level Estimates Using IRS and CMS Data, 2011-2016.

Several studies have shown that Medicaid expansion has improved hospital financial performance. All of these studies have either used data from the Internal Revenue Service (IRS) or the Centers for Medicare and Medicaid Services (CMS), and none of them has examined the state-level impact of expansion on hospital finances. Using data for not-for-profit hospitals from both IRS and CMS for 2011-2016, we described the difference in costs related to uncompensated care and Medicaid shortfalls. We then estimated the impact of Medicaid expansion on hospitals' financial status nationally and by state. Nationally, the estimated net effect of expansion reduced not-for-profit hospital costs by 2 percentage points based on IRS data and 0.83 percentage points based on CMS data. Across expansion states, the estimated net effects varied widely with approximately a 10-fold difference for hospitals based on IRS data and a 2-fold difference based on CMS data. Future studies should further explore the differences across IRS and CMS data.