PROJECT SUMMARY Poverty puts children at risk for developmental delays, lower school achievement and educational attainment, and unfavorable labor market and health outcomes. The Baby’s First Years (BFY) project is the first large-scale randomized controlled trial in the U.S. to estimate the impact of poverty reduction on children’s development and health. Launched in 2018 (NICHD R01HD087384), BFY recruited 1,000 low-income mothers and their newborn infants in four metropolitan areas. Mothers were randomized to receive a monthly unconditional cash transfer of either $333 (“high-cash gift group”) or $20 (“low-cash gift group”) for the first 4 years and 4 months (52 months) of the child’s life. Participants have been followed up annually around the children’s birthdays to measure child development and family life. In this renewal, with funding already in hand for a two-year extension of the cash gifts, BFY has the opportunity to study the impact of poverty reduction for an unparalleled duration, across the first six years of life. The continuation of the project is driven by a need to understand whether continuous monthly cash transfers will improve low-income children’s development at the start of formal schooling. To accomplish this, we will collect two lab-based waves of data, at ages 6 and 8. We will assess high-cash/low-cash group differences at age 6 on measures of academic achievement skills as well as cognitive, self-regulation, and socio-emotional development. We will additionally assess high-cash/low-cash group differences in measures of brain activity and stress physiology. At age 8, we will investigate whether children’s learning and developmental trajectories have been altered in ways that generate persistent impacts, 20 months after the cessation of the payments. The study will also measure family contexts based on two pathways by which poverty is theorized to affect children: an investment pathway (household expenditures; maternal work; activities with children, early care and education arrangements) and a stress pathway (economic hardship; parental relationship quality, maternal mental health, stress, and parenting quality). At both ages 6 and 8, we will assess high-cash/low-cash group differences in these investment and stress pathways.