Because the ACEs public health research shows us that events in childhood can cause “toxic stress” and have a lasting impact on the mental health of a child well into adulthood, this framework provides us with an opportunity to consider how to more effectively intervene to stop the pathway from ACEs to juvenile justice system involvement and address the related health, mental health, developmental, and legal needs of children and their families. Before a child becomes an adult facing a mental health crisis or incarceration, attorneys, doctors, and other professionals can collaborate to disrupt that fate. This Article argues for a more upstream approach to address mental health using a medical-legal collaboration, based on the experiences of the authors, a law professor and medical school professor who work together to try to improve outcomes for children who have experienced trauma and their families.