The landmark National Survey of Child and Adolescent Well-Being (NSCAW) study represents the first effort to gather nationally representative data, based on first-hand reports, about the well-being of children and families who encounter the child welfare system. NSCAW's findings offer an unprecedented national source of data that describe the developmental status and functional characteristics of children who come to the attention of child protective services. Much more than a simple history of placements or length of stay in foster care, NSCAW data chart the trajectory of families across service pathways for a multi-dimensional view of their specific needs. The NSCAW survey is longitudinal, contains direct assessments and reports about each child from multiple sources, and is designed to address questions of relations among children's characteristics and experiences, their development, their pathways through the child welfare service system, their service needs, their service receipt, and, ultimately, their well-being over time. The chapters in this rich synthesis of NSCAW data represent thoughtful and increasingly sophisticated approaches to the problems highlighted in the study and in child welfare research in general. The authors capitalize on the longitudinal, multidimensional data to capture the experiences of children and families from the time they are investigated by CPS though multiple follow-up points, and to consider the interdependent nature of the traditional child welfare outcomes of safety, permanence, and well-being. The topics covered not only are critical to child welfare practice and policy, but also are of compelling interest to other child service sectors such as health, mental health, education, and juvenile justice. The authors of chapters in this volume are esteemed researchers within psychology, social work, economics, and public health. Together they represent the future of child welfare research, showcasing the potential of NSCAW as a valuable resource to the research community and providing glimpses of how the data can be used to inform practice and policy.