The Brief Assessment Checklist for Adolescents (BAC-A) is a 20-item caregiver-report rating scale designed to screen for clinically meaningful trauma- and attachment-related mental health difficulties experienced by adolescents in out-of-home care (foster, kinship, and residential care), as well as children and adolescents adopted from care. The checklist can also be used as a brief casework and treatment monitoring tool by children's agencies and mental health services respectively. It can be safely administered and interpreted by health and social care professionals without clinical training. The BAC-A was derived from the Assessment Checklist for Adolescents (ACA, 105 items).