Adult survivors of childhood maltreatment can be resilient when they have adequate psychosocial resources to cope with maltreatment-related sequelae; however, interpersonal problems may influence the effectiveness of such resources. This study used a schema activation experimental paradigm to test the benefit of social support cognitions on emotional reactivity in adult survivors, while also testing for the moderating role of interpersonal problems and the mediating role of stress appraisal. Young women (N = 126, ages = 18-23) with histories of childhood maltreatment were administered an anger provocation stressor task while their cardiac activity, state anger, and stress appraisals were assessed. Prior to the stressor, women were randomly assigned to either a support schema condition or an acquaintance schema (control) condition, in which they were asked to think and write about either a supportive person or casual acquaintance. The support schema condition demonstrated the least emotional reactivity as evidenced by subjective anger and heart-rate variability, and this outcome was strongest for those with high interpersonal problems. Also, stress appraisals, particularly feeling intimidated, partially mediated the support schema and emotional reactivity relationship. These findings suggest that maltreated women can regulate anger by activating their social support schema. Moreover, support schema may be an important focus of intervention for adult survivors with high interpersonal problems.