Responsibility for cognitive, affective, and behavioral (CAB) health of children and adolescents (hereafter “youth”) has traditionally been shared among families, education systems, communities, and the health care delivery system. Within routine child health care, increasing but spotty attention is paid to early cognitive, emotional, and behavioral development. Those most intensively trained in emotional development and the clinical behavioral sciences (e.g., child and adolescent psychiatrists and psychologists, behavioral and developmental pediatricians, and social workers) have historically been segmented from routine child health care. Roles of behavioral clinicians have focused largely on treating those who have troublesome or disabling CAB disorders. Relatively less attention has been paid by any segment of the health care field to CAB health promotion and disorder prevention, starting early in life, or even to early detection and intervention for behavioral problems of youth who do not meet diagnostic criteria. Much of the innovation in this area has been carried out by prevention scientists who have created evidence-based interventions, primarily targeting activities in community settings, and has not focused on opportunities within primary or subspecialty child health care settings. Preventive interventions adapted for child health care settings and training programs are nascent and will require a revision of training goals and curricula as well as a reorganization of practice for successful implementation.