In comparison to their non-maltreated peers, adult survivors of child maltreatment experience more social and emotional maladjustment; however, survivors can be resilient when they have adequate psychological and social resources to cope with abuse sequelae. Similarly, stress and health studies have shown that social support schemas are stress buffers that attenuate negatively-valenced emotional reactivity. As a result of interpersonal problems, however, some individuals might interpret current relationships more negatively and expect little support in the future. Young women (ages ranging from 18 to 23) with histories of child maltreatment were administered a harassment task while their cardiac activity, emotional states, and stress appraisals were assessed. Before the stressor, the women were randomly assigned to either of two schema priming conditions: thinking and writing about a supportive person (social support schema condition) or a casual acquaintance (control condition). In comparison to women in the control condition, women in the support condition evidenced less state anger and heart rate variability (i.e., rMSSD) reactivity in response to the laboratory stressor; however, the support schema and reactivity relationship did not vary significantly between women with high versus low interpersonal problems. The support schema and state anger reactivity relationship was fully mediated by primary stress appraisals (e.g., feeling challenged and feeling intimidated), but not secondary stress appraisal (e.g., feeling in control). These findings suggest that there are nuances in the relationship between support schema and reactivity. Clinical and research implications are discussed.