The Child Development Supplement (CDS) was started in 1997 to collect information on children and caregivers in families in the USA that participated in the Panel Study of Income Dynamics (PSID), an ongoing national longitudinal household survey that began in 1968. CDS was launched with the goal of creating a comprehensive, nationally representative, prospective database of young children and their families for studying the dynamic process of children's health and development. The same children and their caregivers were interviewed in up to three waves approximately every 5 years (1997, 2002-03, and 2007-08), with a child-based response rate of 90% in the most recent wave. Upon reaching age 18 years and finishing or leaving high school, the children in the CDS cohort shifted to a six-wave follow-up study launched in 2005 called the PSID Transition into Adulthood (TA) study. The TA data have been collected biennially through 2013, with a final wave planned for 2015. Once these young adults form their own economically independent households, they join the PSID. The main categories of data emphasize the major developmental tasks of childhood and young adulthood, including influences on successful development in the domains of family, schools and neighbourhoods. The majority of data and documentation are freely and publicly available through the PSID Online Data Center.