Dependent coverage provision led to uneven insurance gains and unchanged mortality rates in young adult trauma patients.

Insurance coverage has increased among young adults as a result of the Affordable Care Act (ACA) provision that allows young adults to remain covered under their parents' plans until age twenty-six. However, little is known about the provision's effects on the clinical outcomes and insurance coverage of patients with trauma--the most frequent cause of death and physical disability among young adults. Using 2007-12 data from the National Trauma Data Bank, we conducted a difference-in-differences analysis of coverage rates among trauma patients ages 19-25 (compared to patients ages 26-34, who served as the control group), and we examined trauma-relevant outcomes by patient, injury, and hospital characteristics. We found a 3.4-percentage-point decrease in uninsurance status among younger trauma patients following the policy change. The decrease was concentrated among men, non-Hispanic whites, those with relatively less severe injuries, and those who presented to nonteaching hospitals. We did not detect significant changes in the use of intensive care or in overall mortality. The heterogeneous coverage impact of the ACA dependent coverage provision on high- versus low-risk trauma patients has implications for future efforts to expand coverage. Project HOPE—The People-to-People Health Foundation, Inc.