This toolkit, intended for healthcare providers and their teams, provides information and resources on adverse childhood experiences (ACEs) and the developmental and physical harms they may cause. One in four children in Maine experience two or more ACEs, including household dysfunction (parental substance abuse, witnessing domestic violence, loss of a parent), abuse (physical, sexual, and mental), neglect, and neighborhood violence. Children exposed to multiple ACEs have significantly higher rates of developmental delays, anxiety, depression, and other behavioral concerns. This toolkit provides background on ACEs, screening and treatment resources, tools for implementing the Survey of Well-being of Young Children (SWYC) developmental screening, and supporting research. Also included are printable factsheets from the American Academy of Pediatrics Resilience Project.