IntroductionMedical schools have a duty of care to support their students' health and well‐being. Student support studies have tended to focus on outcomes in respect of effectiveness and satisfaction. In contrast, little is known about how student expectations of support may shape their experiences and engagement with support mechanisms, as well as the relationships students have with those offering support (including the institution itself). To address this gap in knowledge, we explore how medical students' expectations of student support systems shape, and are shaped by, institutional rules and processes.MethodsWe employed a qualitative case study approach using an institutional ethnography informed methodology. Our context was a medical school that provides a well‐advertised, formal institutional support system where students are assigned a personal tutor. Data collection included interviews with medical students (n = 13) plus document analysis (public facing artefacts and internal policies/guidelines related to the support system). We applied the lens of psychological contract theory to guide abductive analysis of interview and text data.ResultsStudents expected a strong support system to be provided by the medical school and the personal tutors. However, their experiences did not always align with their expectations. Some felt excluded by the system while others regarded the relationship with their personal tutor as more transactional than relational. Where their expectations were unmet, students responded by reducing their engagement with the formal support system and creating their own peer‐support network that supplemented existing formal support.DiscussionStudent expectations matter in shaping their experiences of support systems. Where expectations are unmet, students may disengage and/or find alternatives. This may be easier for some students compared with others. More understanding of the relationship between expectations and engagement with support can inform the development of institutional support structures that meet the needs of all students across time.