Child maltreatment impacts approximately one in seven children in the United States, leading to adverse outcomes throughout life. Adolescence is a time period critical for the development of executive function, but there is little research examining how abuse and neglect may differently affect the developmental trajectories of executive function throughout adolescence and into young adulthood. In the current study, 167 adolescents participated at six time points from ages 14 to 20. At each time point, adolescents completed behavioral tasks measuring the three dimensions of executive function (working memory, inhibitory control, and cognitive flexibility). Neglect and abuse in early life (ages 1–13) were reported at ages 18–19. Unconditional growth curve models revealed age-related improvement in all three executive function dimensions. Conditional growth curve models tested the prospective effects of recalled neglect and abuse on the developmental trajectories of executive function. The results revealed that neglect was associated with developmental changes in working memory abilities, such that greater levels of neglect during ages 1–13 were associated with slower increases in working memory abilities across ages 14–20. These findings highlight the adverse consequences of early neglect experiences shown by delayed working memory development during adolescence into young adulthood.