In an attempt to suggest ecologically sensitive program models which are developmentally responsive to the needs of adolescent parents and their children, this paper reviews existing research to identify the critical ecologies in their lives, evaluates existing program models for their ecological sensitivity, and presents a case study of the ecological approach in practice. Drawing from Bronfenbrenner's ecological perspective and typology of systems, the paper identifies family, partner, school, work, health care, neighborhood, poverty, and ethnicity as critical ecological systems in the lives of the adolescent and her child. Many existing program models do not systematically address all of these critical systems. The Ounce of Prevention Fund's multiple layers of partnership model is presented as a realistic and effective approach to providing services that address the critical system needs of adolescent parents and their children.