The pairwise overlaps in system involvement between child protective services, mental health services, and the criminal justice system is well-documented. Yet, less is known about how contact to these three systems evolves as children age, and how children’s trajectories through these institutions should be conceptualized. In this article, we use administrative data on the full population of Danish children born 1982-1995 that had contact to at least one of three systems before turning 21. Theoretically, we argue that children’s trajectories of institutional contacts can be understood as a moral career as suggested by Goffman (1959). Empirically, we study how children move between and are retained within the three systems across childhood. We find that early contact originates with child protective services but branch out through both overlap and transitions to the other systems. Further, across age there is high levels of retention within the systems, and clear gendered dynamics play out as children age. We argue that children’s trajectories across age can be viewed as moving from a position as a subject at risk to a position as subject of risk.