Early adversity exposure impacts many children annually, putting them at risk of prospective health problems. This study tests whether participating in a behavioral parent training intervention predicts differences in a biomarker predictive of health outcomes, epigenetic age acceleration, in a sample of majority Latinx three-year-old children (n = 62) with developmental delay and elevated behavioral problems. Participation in the parenting intervention was unrelated to a) between-group differences in epigenetic age acceleration at follow-up and b) differences in within-group change from baseline to follow-up. However, some evidence suggested the presence of an effect of parent training on decreased epigenetic age acceleration may be present. Adversity exposure (measured using cumulative risk) interacted with changes in observed positive and negative parenting to predict differences in epigenetic age acceleration at follow-up. When parenting improved, children exposed to higher levels of cumulative risk demonstrated lower epigenetic age acceleration at follow-up. Findings suggest behavioral parent training may alter the biological embedding of stress in underserved, adversity-exposed children.