The Attachment, Self Regulation, and Competency (ARC) Framework is a theoretically grounded, evidence-informed, promising practice used to treat complex trauma in children and adolescents. This article introduces the ARC model and describes its application with young children of diverse ethnocultural backgrounds involved in the child protection system due to maltreatment. Examination of the clinical application of the ARC model with this population underscores the importance of grounding child complex trauma treatment in the caregiving system.