This study expanded the Benevolent Childhood Experiences scale (termed the “BCEs-Original” scale) with 10 new multisystem items and identified a subset of items (termed the “BCEs-Revised” scale) that are systematically less commonly reported across samples. Total BCEs-Revised scores were tested against total BCEs-Original scores and three dimensions of childhood adversity (maltreatment, threat, and deprivation) as predictors of young adulthood mental health problems (depression, anxiety, and PTSD symptoms). Hypotheses expected stronger inverse associations of BCEs-Revised scores than BCEs-Original scores with all mental health problems. Participants were 1,746 U.S. young adults (M = 26.6 years, SD = 4.7, range = 19–35 years; 55.3% female, 42.4% male, 2.3% gender non-conforming; 67.0% White, 10.3% Asian, 8.6% Black, 8.4% Latine, 5.7% other) who completed a 20-item BCEs scale and well-validated instruments on childhood adversities and mental health problems. Compared to BCEs-Original scores, BCEs-Revised scores were significantly more strongly inversely associated with all mental health outcomes. Compared to childhood threat and deprivation, maltreatment was significantly more strongly associated with PTSD symptoms. After controlling for current depression symptoms, BCEs-Revised scores interacted with maltreatment to predict PTSD symptoms. Maltreatment and BCEs-Revised scores also influenced PTSD symptoms in person-oriented analyses. The BCEs-Revised scale has strong psychometric properties and unique strengths in research and practice. Implications for multisystem resilience are discussed.