This study used a structural equation mixture model to examine associations between child maltreatment, polygenic risk, and indices of adaptive functioning. Children aged 6 to 13 years (N = 1,004), half maltreated, half nonmaltreated, were recruited to attend a research day camp. Multi-informant indicators of prosocial behavior, antisocial behavior, withdrawn behavior, and depression were collected and used in a latent class analysis. Four classes emerged, characterizing “well-adjusted,” “externalizing,” “internalizing,” and “socially dominant” groups. Twelve genetic variants, previously reported in the Gene × Environment literature, were modeled as one weighted polygenic risk score. Large main effects between maltreatment and adaptive functioning were observed (Wald = 35.3, df = 3, p < .0001), along with evidence of a small Gene × Environment effect (Wald = 13.5, df = 3, p = .004), adjusting for sex, age, and covariate interaction effects.