OBJECTIVE: Family functioning influences various psychosocial outcomes for individuals with pediatric chronic health conditions (e.g., Leeman, J., Crandell, J. L., Lee, A., Bai, J., Sandelowski, M., & Knafl, K. (2016). Family Functioning and the Well-Being of Children With Chronic Conditions: a Meta-Analysis. Research in Nursing & Health, 39, 229-243), but this has not been examined among families of youth with differences of sex development (DSD). The objective of this study was to examine (a) differences in family functioning based on DSD-related and demographic characteristics, (b) the associations between family functioning and psychosocial outcomes, and (c) the moderating effects of current age. METHODS: Participants were 57 adolescents and 40 young adults (AYA) ages 12-25 years (M = 16.97) with DSD resulting in atypical genital appearance and/or discordance between phenotypic and chromosomal sex who participated in a cross-sectional study examining psychosocial outcomes. Participants completed the Family Environment Scale, the McMaster Family Assessment Device, the Perceived Acceptance Scale, and outcome measures including the Youth Self-Report/Adult Self-Report and the Connor-Davidson Resilience Scale. Analyses included t-tests and linear regressions with moderation effects. RESULTS: AYA reported better family functioning if they were diagnosed at a younger age, learned about their diagnosis at a younger age, had 46, XY karyotype, and identified as male. General family functioning, family conflict, and family acceptance had the strongest associations with psychosocial outcomes. Greater family acceptance was associated with fewer total problems, and this association was stronger for adolescents (ps <
.05). CONCLUSIONS: AYA with certain DSD-related characteristics may demonstrate more adaptive family functioning. Family functioning is strongly associated with psychosocial outcomes for AYA with DSD. Results highlight the importance of developing family-focused interventions to promote psychosocial functioning in AYA with DSD.