Background: Prior studies of the impact of the Affordable Care Act on reimbursement for inpatient trauma care do not include disproportionate share hospital (DSH) funding. Because trauma centers and other safety-net hospitals are sensitive to any changes in financial support, it is essential to include DSH funding in evaluating overall reimbursement. This study analyzes the long-term financial trends, including DSH, of a level I trauma center in Ohio, a state that expanded Medicaid. Methods: Charges, reimbursement, sources of insurance coverage, Injury Severity Scores, and DSH funding for the trauma patient population of an Ohio American College of Surgeons level 1 trauma center were studied from 2012 to 2017. Data were collected from Transition Systems, Inc. Results: During 2012-2017, self-pay patient cases decreased from 15.0% to 4.1% and commercial insurance patients decreased from 34.2% to 27.6%. The percentage of Medicaid patients increased from 15.5% to 27.1%; however, Medicaid reimbursement average per case declined from $17,779 in 2012 to $10,115 in 2017 (a decline of 43.1%). Self-pay charges decreased from $22.0 million to $6.7 million. Total DSH funding, compensation given to hospitals that disproportionately treat underserved populations, decreased 17.4%. Conclusions: Self-pay charges and self-pay patients decreased dramatically; Medicaid patients and charges increased substantially in the years after the implementation of the Affordable Care Act at our trauma center. However, there was a decrease in commercial insurance, which had the highest reimbursement for our hospital, and a significant decline in DSH, a critical supplemental source of funding for safety-net hospitals.