In an analysis of whether the expansion of Medicaid under the ACA resulted in changes to emergency department visits, former PSC trainee Sayeh Nikpay, former PSC post-doc Seth Freedman, and PSC researchers Helen Levy and Thomas Buchmueller examined data from 14 states that expanded Medicaid in 2014 and 11 states that did not. They found a decline in emergency visits for uninsured patients and an increase for insured patients in expansion states.