There has been growing interest among parents, teachers, researchers, and policymakers in better understanding children's school readiness and the precise mechanisms by which early care and education programs promote these early skills. Two key, but understudied, mechanisms include preschool instruction and parenting practices. The present study used the Family and Child Experiences Survey (FACES) 2006 cohort and examined whether gains in young children's (n = 2,308) math, literacy, and behavior problems over the Head Start year were predicted by increased stimulation across children's homes and school using structural equation modeling. Net of all other factors, parent learning support was uniquely associated with lower levels of behavioral problems and greater math achievement. Although there were no direct effects of parent involvement on child outcomes, the effects of parent involvement on children's math and behavior were mediated through parent learning support. Children also demonstrated reduced problem behaviors when they received greater teacher instruction. However, the observed benefits for math achievement and reduced problem behaviors appear to be stronger when young children receive stimulation across both the home and school contexts. These findings have implications for children's early problem behaviors and achievement, suggesting that parenting practices and teacher instruction are important avenues that can promote young children's early skills. For optimal academic and behavioral outcomes, however, greater effort needs to be coordinated across children's home and school settings. (author abstract)