The Federal Interagency Forum on Child and Family Statistics' primary mission is to enhance data collection and reporting on children and families. "America's Children: Key National Indicators of Well-Being, 2013" provides the Nation with a summary of national indicators of children's well-being and monitors changes in these indicators. The purposes of the report are to improve reporting of Federal data on children and families, make these data available in an easy-to-use, non technical format, stimulate discussions among policymakers and the public, and spur exchanges between the statistical and policy communities. There are many interrelated aspects of children's well-being, and only selected facets can be included in this report. This report draws on various overarching frameworks to identify seven major domains that characterize the well-being of a child and influence the likelihood that a child will grow to be a well-educated, economically secure, productive, and healthy adult. The seven domains are family and social environment, economic circumstances, health care, physical environment and safety, behavior, education, and health. These domains are interrelated and can have synergistic effects on well-being. Each section of the report corresponds to one of the seven domains and includes a set of key indicators. These indicators either characterize an aspect of well-being or an influence on well-being. These are: (1) Family and Social Environment; (2) Economic Circumstances; (3) Health Care; (4) Physical Environment and Safety; (5) Behavior; (6) Education; and (7) Health. Appended are: (1) Detailed Tables; and (2) Data Source Descriptions. (Contains 68 tables and 159 notes.)