Background: Low rates of referral to specialty care among Veterans represent a significant barrier to access and optimal clinical outcomes. This is particularly true for Veterans with end-stage organ diseases (e.g., advanced chronic kidney disease (CKD), decompensated cirrhosis), who are potentially eligible for life-saving transplantation and require specialty care for optimal disease management. Despite the high prevalence of end-stage liver and kidney diseases among Veterans, less than a third of Veterans with advanced CKD and decompensated cirrhosis are referred to a specialist and <5% for transplant evaluation. A comprehensive assessment of patient-, provider- and system-level factors influencing specialty care referral and referral for transplant evaluation is critical to developing targeted strategies and approaches to optimize referral appropriateness as there is a clear association between being seen by a specialist and improved survival. Significance/Impact: Ensuring timely access to high-quality primary and specialty care is a core mission of the Veterans Health Administration (VHA). Factors affecting specialty care referral and referral for transplant evaluation among Veterans with advanced chronic liver and kidney diseases are incompletely characterized. This knowledge is critical to designing effective strategies to enhance referral appropriateness and optimize access. Hence, there is an urgent unmet need to improve our understanding of these complex relationships and the mechanisms by which they affect referral to specialty care and referral for transplant evaluation. Innovation: Most existing work has focused on steps downstream of referral to specialty care and for transplant evaluation, such as completion of transplant evaluation, waitlisting, transplant receipt, and post- transplant outcomes -- thus, barriers to specialty care referral and referral for transplant evaluation remain understudied. This study will comprehensively examine and identify