To examine the association between preschool-aged children's exposure to adverse childhood experiences (ACEs) and multiple, intersecting domains of school readiness using a nationally representative sample.

A sample of 15 402 preschool-aged children (3-5 years) in the US from the 3 most recent cohorts (2016-2018) of the National Survey of Children's Health were employed. Primary caregivers were asked survey questions about the adversities experienced by focal children. Four distinct domains of school readiness among the children were also derived from the survey: early learning skills, self-regulation, social-emotional development, and physical health and motor development.

Although nearly one-half of children who had not been exposed to ACEs were on-track across all domains, only 1 in 5 children exposed to 3 or more ACEs were on-track across all domains. Follow-up analyses identified parenting stress and reduced positive parenting practices as significant mediators of this association. Multivariate results also indicated that, regardless of the school readiness domain examined, an accumulation of ACEs increased the rate of items on which a child needs support or is at-risk.

An accumulation of ACEs among preschool-aged children elevates risk within and across school readiness domains. These findings highlight the urgent need to identify best practices to reduce ACE exposure, as well as improve school readiness during early childhood.