This article describes innovative service delivery models and clinical strategies that support the social-emotional development of young children and their families in the pediatric primary care setting. By understanding the trends affecting well-child care, early childhood providers will be better equipped to partner with their pediatric counterparts on behalf of the families both serve. First, the authors describe an emerging model in behavioral health care that provides the backdrop to current efforts to integrate social-emotional developmental services into primary care: the integrated behavioral health care model of care. Two programs highlighted in a recent Substance Abuse and Mental Health Services Administration study of pediatric primary care sites serving young children demonstrate how they have integrated behavioral health services in their programs. The article also describes clinical approaches for infusing social-emotional supports into primary care and provides a snapshot of promising applications of computer technology for psychosocial screening in primary care.