PROJECT SUMMARY/ABSTRACT Although survival of children receiving kidney replacement therapy (KRT, including kidney transplantation, hemodialysis, and peritoneal dialysis) has steadily improved over time, kidney failure continues to confer significant mortality risk. This increased risk continues into young adulthood: those aged 18-44 years have the highest rates of emergency department use, hospitalization, and 30-day readmissions of all patients with kidney failure, even though these younger patients have fewer comorbidities than older patients receiving dialysis. Kidney transplantation is the preferred KRT modality for patients of all ages, followed by home dialysis options (home hemodialysis or peritoneal dialysis). Yet, over 60% of adolescents and young adults initiate dialysis with in-center hemodialysis, which is associated with worse survival as compared to home-based options. Disappointingly, less than 20% of those aged 13-17 years and even fewer young adults receive preemptive transplantation, which is suboptimal given the presence of parents who could serve as potential living donors. The complex care coordination underlying the transplant waitlist activation and living donor identification processes are often spearheaded by social workers within dialysis facilities. Inadequate access to social workers may be a barrier to attainment of living donor transplantation, especially in a younger and more vulnerable population who may have lower levels of self-efficacy and require more support than older adults to navigate a complex healthcare system. We seek to identify facilitators and barriers to adolescents’ and young adults’ pursuit of optimal KRT modalities. This training plan will equip Dr. Bicki with the statistical, mixed-methods, and hands-on skills needed to design future interventions to increase uptake of preferred modalities. UCSF provides an excellent training environment to conduct this proposal, given it is one of the largest transplant centers in the United States, and has unique tools available to enable qualitative analysis. Our specific aims are: Aim 1: To examine the association between patient-to-social worker ratio at dialysis facilities and access to transplantation among adolescents and young adults (aged 14-21 years) with kidney failure treated with dialysis using the US Renal Data System, the national end-stage kidney disease registry. Aim 2: To use a mixed-methods approach to identify facilitators and barriers to home dialysis and transplantation among adolescents and young adults (aged 14-21 years).