Investment in violence prevention programs is hampered by lack of clearly identifiable stakeholders with a financial stake in prevention. We determined the total annual charges for the acute care of injuries from interpersonal violence and the shift in financial responsibility for these charges after the Medicaid expansion from the Affordable Care Act in 2014.

We analyzed all emergency department (ED) visits from 2009 to 2014 with diagnosis codes for violent injury in the Nationwide Emergency Department Sample (NEDS). We used sample weights to estimate total charges with adjusted generalized linear models to estimate charges for the 15% of ED visits with missing charge data. We then calculated the share attributable by payer and determined the difference in proportion by payer from 2013 to 2014.

Between 2009 and 2013, the uninsured accounted for 28.2–31.3% of annual charges for the acute care of violent injury, while Medicaid was responsible for a similar amount (29.0–31.0%). In 2014, there were $10.7 billion in total charges for violent injury. Medicaid assumed the greatest share, 39.8% (95% CI: 38.0–41.5%, $3.5–5.1 billion), while the uninsured accounted for 23.6% (95% CI: 22.2–24.9%, $2.0–3.0 billion), and Medicare accounted for 7.8% (95% CI: 7.7–8.0%, $0.7–1.0 billion).

After Medicaid expansion, taxpayers are now accountable for nearly half of the $10.7 billion in annual charges for the acute care of violent injury in the U.S. These findings highlight the benefit to state Medicaid programs of preventing interpersonal violence.