Project Summary The highest rates of mortality, acute care encounters, and re-hospitalizations for patients with sickle cell disease (SCD) occur among 18–30 year olds, after the transfer from a pediatric to an adult healthcare provider. Barriers to successful transition from pediatric to adult care include a lack of support, minimal transition planning, providers' lack of time to address transition issues, and disparities in care related to the racial background of the patients. However, effective transition programs for individuals with SCD are lacking. The proposed project aims to address this gap by developing and evaluating the feasibility of a novel transition mentoring program to improve the transition readiness and health outcomes of adolescents and young adults (AYA) with SCD. Guided by the Social-Ecological Model of Adolescent and Young Adult Readiness to Transition (SMART) framework, the intervention will target patient self-management skills, knowledge, and confidence in navigating the adult healthcare system through the specialized peer support offered by a medical student mentor familiar with the pediatric and adult hematology clinics. Medical students were chosen as mentors because they uniquely have specialized knowledge of the healthcare system and serve as similar-aged “peers” who can offer developmentally appropriate support to the patient. In Phase 1, we will conduct individual interviews to identify patient barriers, expectations, fears, and perspectives about transitioning to adult care to be addressed by the medical student mentoring program (Aim 1). These interviews will inform the mentoring intervention content. In Phase 2, we will conduct a pilot feasibility study of the medical student mentoring program (Aim 2) and examine acceptability, usability, and satisfaction with the intervention by AYA with SCD and mentors. We will examine the impact of the intervention on patient outcomes (transition readiness, health-related quality of life, and medication adherence) and medical student outcomes (attitudes towards chronic illness and empathy) (Exploratory Aim). We expect that the program will provide benefit for both the AYA patients and the medical student mentors.