Concern for social inequalities in health in the United States is increasingly becoming part of the mainstream public health and health research agenda. Responding to organized efforts within and outside the health sector, the Department of Health and Human Services (DHHS) is supporting programs dedicated to eliminating social disparities in health, and within DHHS, the National Institutes of Health (NIH) are supporting research into health disparities. The NIH Office of Research on Women’s Health (founded in 1990) and the new National Center on Minority Health and Health Disparities (including socioeconomic disparities) are, for example, focusing attention on multiple health outcomes in relation to specified social determinants, rather than parsing out ailments solely by body parts. At issue are ways in which population patterns of health, disease, and well-being, from conception to death, reflect societal conditions, including social inequality, across the lifecourse.