Socioeconomic conditions are known to be major determinants of health at all stages of life, from pregnancy through childhood and adulthood. Life-course epidemiology has added a further dimension to the understanding of the social determinants of health by showing an association between early-life socioeconomic conditions and adult health-related behaviors, morbidity, and mortality. Sensitive and critical periods of development, such as the prenatal period and early childhood, present significant opportunities to influence lifelong health. Yet simply intervening in the health system is insufficient to influence health early in the life course. Community-level approaches to affect key determinants of health are also critical. Many of these issues were raised in the 1995 National Academies book, Children’s Health, the Nation’s Wealth. The present volume builds upon this earlier book with presentations and examples from the field. Focusing on Children’s Health describes the evidence linking early childhood life conditions and adult health; discusses the contribution of the early life course to observed racial and ethnic disparities in health; and highlights successful models that engage both community factors and health care to affect life course development.