ABSTRACT Intergenerational transmission of inequalities in economic and social wellbeing, including health, in the United States has been well documented and shown to account for a substantial portion of contemporary disparities by SES and race and ethnicity in these domains. Yet, due to a paucity of population-based longitudinal data on family contexts, parenting, and child development across multiple generations, knowledge of the extent to which these factors may be key mechanisms for intergenerational transmission of inequalities is limited. The Future of (formerly Fragile) Families and Child Wellbeing Study (FF) is the only ongoing population-based birth cohort study in the U.S. to currently follow three generations of family members. FF follows the parents (first generation; G1) of initial birth cohort children (G2; born 1998-2000) and the G2 children (now young adults). Survey and biological data are now being collected on all children born to G2 sample members (G3) as soon as possible after their birth and will be collected on G2s at age 27. Data span economic, social, environmental, and biological factors for each generation within a large and diverse national sample. The proposed study will expand FF to include data at age 5 for all (G3) children born to G2 women. The project aims to: (1) Collect data on family/caregiving context, parenting and grandparenting behaviors, and child health, socioemotional development, achievement (cognition), and executive function for all G3 children born to female G2 respondents as they reach age 5; (2) Prepare all data and accompanying documentation to be publicly available to the research community and fully linkable to all other FF data sources within 1 year of the end of the award period; (3) Produce a comprehensive guide for implementing virtual assessments of children and families in the context of a large-scale national study with specific attention to logistical considerations, response rates, potential challenges (connectivity and quality therein, household distractions, child attention and comprehension), and lessons learned, both overall and for particular subgroups of families; and (4) Conduct preliminary analyses of intergenerational correlations of family context/caregiving environment, economic resources, parenting behaviors, and child development among disadvantaged families. These data will support novel and important studies of intergenerational transmission of family context, economic resources, parenting behaviors, and child development; whether associations of family context, economic resources, and parenting behaviors with child development are consistent or differ across generations; and whether there is heterogeneity in these patterns by population characteristics. They will also (eventually) support epigenetic analyses via DNA-based, sociodemographic, and environmental information on three generations, including prenatal, perinatal, and early childhood data on G2 and G3. As such, ...