Unmet need for behavioral health care is a serious problem for crossover youth, or those simultaneously involved with the child welfare and juvenile justice systems. Although a large percentage of crossover youth are serious emotionally disturbed, relatively few receive necessary behavioral health services. Few studies have examined the role of interagency collaboration in facilitating behavioral health service access for crossover youth. This study examined associations for three dimensions of collaboration between local child welfare and juvenile justice agencies - jurisdiction, shared information systems, and overall connectivity - and youths' odds of receiving behavioral health services. Data were drawn from the National Survey of Child and Adolescent Well-Being, a national survey of families engaged with the child welfare system. Having a single agency accountable for youth care increased youth odds of receiving outpatient and inpatient behavioral health services. Inter-agency sharing of administrative data increased youth odds of inpatient behavioral health service receipt. Clarifying agency accountability and linking databases across sectors may improve service access for youth involved with both the child welfare and juvenile justice systems.