Evaluations of integrated care programs share many characteristics of evaluations of other complex health system interventions. However, evaluating integrated care for child and adolescent mental health poses special challenges that stem from the broad range of social, emotional, and developmental problems that need to be addressed; the need to integrate care for other family members; and the lack of evidence-based interventions already adapted for primary care settings. Integrated care programs for children’s mental health need to adapt and learn on the fly, so that evaluations may best be viewed through the lens of continuous quality improvement rather than evaluations of fixed programs.