The development, care, and education of children from birth to age 5 has been the focus of rapidly increasing public interest, and numerous early childhood public policy initiatives have focused attention on a major problem of coordination and collaboration of services for young children. Four segments of services for young children--(1) child care, (2) Head Start, (3) services for children with disabilities, and (4) preschool programs--have all been major players in providing services for differing, and sometimes overlapping, populations of young children. Each group has a similar mission: to help children (most often with special needs or limited opportunities) master the skills and knowledge needed to adapt effectively to kindergarten at age 5. Each group has its own history and has developed more or less independently of the others. Because the groups developed independently, they have overlapping personnel preparation programs, evaluation efforts, and data systems. This paper explores some strategies for moving from independent and overlapping services toward a seamless system of early child care and nurturance provided by these four diverse players. Voluntary collaborations between these players seem unlikely because of self-interest and bureaucratic challenges. Barriers to reform exist in institutional, psychological, sociological, economic, political, and geographic domains. This paper proposes that four engines of change--legislation, court decisions, administrative rule making, and professional initiatives--be energized to move toward a seamless system. Such collaboration can begin by merging support systems such as personnel preparation, technical assistance, and evaluation. The paper concludes with specific recommendations for achieving an integrated early childhood system.