Background: Kidney failure is a highly morbid condition that affects 13,000 new Veterans every year, 60% of whom die within 5 years. Most Veterans with kidney failure receive in-center hemodialysis, which requires Veterans to travel several times per week to a dialysis center. Some Veterans perform dialysis at home, usually as peritoneal dialysis (PD). However, while PD can provide similar or better quality of life at lower costs, Veterans with kidney failure have limited and inequitable access to PD. Only 5% of Veterans with kidney failure receive PD—compared to 17% of civilians—and Black patients are 31% less likely to receive PD compared to White patients. My long-term goal as a nephrologist is to lead research that will increase equitable access to PD so that every Veteran with kidney failure has the option to safely choose to perform dialysis at home. As a first step towards this goal, my mentorship team and I conducted site visits to four VA PD clinics across the country to better characterize home dialysis practice patterns within VA. At these site visits, Veterans and clinicians identified peer support as a potential implementation strategy to address barriers to home dialysis use while also simultaneously identifying that there are critical gaps in VA’s understanding of care delivery in home dialysis that first need to be addressed to enhance the acceptability, feasibility, and sustainability of a peer support program. In this CDA proposal, I aim to address these gaps in our understanding of home dialysis use while also co-designing and pilot-testing peer support as an implementation strategy to address inequities in home dialysis use within VA. To accomplish these research objectives and transition to independence, I seek to complete training in 1) advanced qualitative methods (including triangulation of multiple methods), 2) human-centered design, and 3) implementation science trials. Significance: Expanding equitable access to PD aligns with at least 4 operational priorities: i) VHA’s priority to expand home care service options for older Veterans, ii) the VA National Kidney Program Office’s priority to expand equitable access to PD, iii) the VA Office of Integrated Veteran Care’s priority to expand access to home dialysis for Veterans, and iv) the VA Office of Health Equity’s goal to achieve equitable health care for marginalized Veterans, including Veterans with kidney disease who are disproportionately Black. Innovation: This proposal represents a novel approach to co-develop a VA peer support program for dialysis, a physical illness with distinct challenges compared to mental illness (for which VA has a successful peer specialist program). It will outline a pathway for co-designing peer support for other chronic illnesses (such as heart failure) that will benefit from early and frequent input from a diverse group of Veterans and clinicians. Specific Aims: 1) Use a qualitative approach to characterize barriers at each phase of the ...