The purpose of the Integrated Fertility Survey Series (IFSS) is to create a harmonized data set of ten component surveys of fertility and family growth. Integration of these data sets will allow for easier and more efficient use of family and fertility data over time. Data were harmonized from ten component studies of family and fertility, including the 1955 and 1960 Growth of American Families studies, 1965 and 1970 National Fertility Surveys, and the 1973, 1976, 1982, 1988, 1995, and 2002 National Surveys of Family Growth. IFSS staff harmonized all concepts that appeared in at least five of the component studies. In special cases, concepts that appear in as few as two component studies were also harmonized. Comparability notes, located on the IFSS Web site, outline the processes by which data were harmonized.