Transplantation programs commonly rely on clinicians’ judgments about patients’ social support (care from friends or family) when deciding whether to list them for organ transplantation. We examine whether using social support to make listing decisions for adults seeking transplantation is morally legitimate, drawing on recent data about the evidence-base, implementation, and potential impacts of the criterion on underserved and diverse populations. We demonstrate that the rationale for the social support criterion, based in the principle of utility, is undermined by its reliance on tenuous evidence. Moreover, social support requirements may reinforce transplant inequities, interfere in patients’ personal relationships, and contribute to biased and inconsistent listing procedures. As such, accommodating the needs of patients with limited social support would better balance ethical commitments to equity, utility, and respect for persons in transplantation. We suggest steps for researchers, transplantation programs, and policymakers to improve fair use of social support in transplantation.