ABSTRACT. Suicide is the eighth leading cause of death in children ages 5-11, and recent evidence suggests that rates of suicide are rising disproportionately in Black children. Further, self-injurious thoughts and behaviors (SITB) – which increase risk for suicide death -- account for a rising proportion of children's hospital emergency department and inpatient visits. Preteens in the child welfare system (CWS) are at even greater risk for suicide than those in the general population. However, few studies have investigated risk and protective factors, adolescent outcomes, or examined change in SITB over time in preteens involved in the CWS. Understanding the pathways between child maltreatment (CM) and SITB in preteens, as well as trajectories and adolescent outcomes of preteen SITB is critical to identify and prevent suicide in CWS-involved children. The proposed exploratory/developmental study will integrate two rich, longitudinal datasets that followed children involved in the CWS, which is the entity that investigates CM when a report is made. These data allow for exploration of risk pathways, outcomes, and longitudinal patterns of change within CWS-involved children. Further, because the two studies were so consistent in design and measures, data integration will allow for more nuanced investigations of preteen SITB in the CWS. The proposed study will identify mechanisms that confer vulnerability to child suicide risk, discover novel targets for future therapeutic intervention, and identify early signs of risk that could represent targets for future prevention and treatment studies. Findings from this study will advance the science on preteen suicide risk—an area urgently in need of investigation. Importantly, the study will help to identify targets for suicide prevention among children in the CWS, a vulnerable and underserved group.