SUMMARY/ABSTRACT Hypospadias, a urethral opening on the underside of the penis, is one of the most common birth defects in boys (1 in 250 newborns). Left untreated, hypospadias may affect quality of life, cosmetic appearance, urination, sexual function, and fertility. Currently, parents must make this important, preference-sensitive treatment decision with neither evidence-based guidance nor a clearly superior option. Consequently, 55-71% of parents experience decisional regret regardless of whether they choose surgery which is strongly associated with decisional conflict. We aim to reduce parental decisional conflict and regret by improving information delivery through use of a shared decision-making (SDM) tool called the Hypospadias Hub. It was developed and pilot-tested at two U.S. sites by our team. The objective of this proposal is to conduct a type 1 hybrid effectiveness-implementation study of the Hypospadias Hub Intervention. Our two-arm randomized controlled trial will assess its effectiveness to: 1) improve quality of SDM during hypospadias consultations as measured by parent report (primary outcome), and observer report (secondary outcome), 2) decrease decisional conflict and regret, and increase decision-relevant hypospadias knowledge (secondary outcomes). We will also assess barriers and facilitators to its future implementation. Our aims are 1. Compare the effect of the Hypospadias Hub Intervention vs. control on the quality of SDM (primary outcome). We will assess how providers influence parents’ choices using qualitative content analysis of transcripts of the consultations. Parents will be randomized to the respective arms of the study. Hypothesis: The quality of SDM during the consultation will be higher in the intervention than the control group. 2. Compare the effect of the Hypospadias Hub Intervention vs. control on decisional conflict, decision-relevant knowledge, and decisional regret (secondary outcomes). Hypothesis: Decisional conflict and regret will be lower, and knowledge higher in the intervention vs. control group. 3. Assess barriers and facilitators to future implementation using constructs from the Consolidated Framework for Implementation Research. We will use qualitative interviews with a diverse sample of parents, providers, nurses, and clinic staff to explore recommendations for implementation, and potential future implementation strategies. Evidence of the effectiveness of the Hypospadias Hub Intervention to improve quality of SDM and decision quality for parents making decisions about hypospadias, combined with insights gained from our implementation assessment, will support wider adoption, and inform development of tools for other preference-sensitive decisions, which will improve child health and quality of life.