Child care and early education programs serve diverse needs for children and families, from promoting children’s early cognitive, language, and social skills and helping to prepare them for formal schooling, to supporting parental employment, to promoting equality and cultural norms. As such, governments across many countries are directing resources towards supporting accessible and high quality early childhood programs, using diverse policy levers such as quality regulations, federal or state subsidies, and tax breaks. Literature on the effects of early childhood education programs have found that center-based and high quality programs help to promote children’s early academic skills, including nascent language, reading, and math skills that are critical for a successful entry into formal schooling and continued school success. There are more mixed results, however, concerning whether such programs support or may hinder children’s social functioning, including their aggressive behaviors and peer skills. The vast majority of the literature on early childhood programs derives from U.S. studies, with much drawn from two very distinct populations: intensive early intervention programs with low-income, primarily African American children; or large-scale survey and quasi-experimental work with primarily middle-class and white children. As such, we have limited knowledge concerning other policy models of early childhood care and education, and of whether effects of center-based and high quality care are generalizable to other populations and other policy and cultural environments. To address this issue, this panel includes four studies of the effects of early care and education programs on young children’s school readiness skills (early language, cognitive, and behavioral skills), drawn from four very distinct populations and policy contexts. The first uses a representative sample of Australian children (a country with strong quality controls and government financial subsidies for child care) to address whether the type and extent of care during infancy, toddlerhood, and preschool are associated with children’s cognitive and behavioral skills after school entry. The second paper looks at Norway, a country with very high rates of early care use and childcare quality, exploiting a recent policy change in care availability to address whether toddler-age care promotes language skills, and whether this association is moderated by family income. The third paper assesses a recent intervention in Chile designed to improve the quality of preschool care and hence increase positive impacts on children’s language skills. The final paper assesses children in immigrant families in the U.S., considering whether the benefits of preschool programs are stronger or weaker for children facing language and cultural barriers to school success. Together, this set of papers seeks to notably expand our knowledge concerning the generalizability of the effects of early care and education programs on children’s development, and to compare and contrast policy models across numerous countries.