Childhood maltreatment has lasting negative effects throughout the life span. Early intervention research has demonstrated that these effects can be remediated through skill-based, family-centered interventions. However, less is known about plasticity during adolescence, and whether interventions are effective many years after children experience maltreatment. This study investigated this question by examining adolescent girls' ability to make advantageous decisions in the face of risk using a validated decision-making task; performance on this task has been associated with key neural regions involved in affective processing and executive functioning. Maltreated foster girls (n = 92), randomly assigned at age 11 to either an intervention designed to prevent risk-taking behaviors or services as usual (SAU), and nonmaltreated age and socioeconomic status matched girls living with their biological parent(s) (n = 80) completed a decision-making task (at age 15-17) that assessed risk taking and sensitivity to expected value, an index of advantageous decision making. Girls in the SAU condition demonstrated the greatest decision-making difficulties, primarily for risks to avoid losses. In the SAU group, frequency of neglect was related to greater difficulties in this area. Girls in the intervention condition with less neglect performed similarly to nonmaltreated peers. This research suggests that early maltreatment may impact decision-making abilities into adolescence and that enriched environments during early adolescence provide a window of plasticity that may ameliorate these negative effects.