["Bioethics, EarlyView. ", "\nABSTRACT\nMarginalization is a widely studied phenomenon and recognized as a critical topic in relation to health, shaping health inequities, access to resources, health outcomes, and policy decisions. However, despite its normative importance for health and justice, its conceptual role in bioethics remains unclear. This paper critically examines how marginalization is addressed in bioethics, analyzing its meaning, conceptual usage, and potential for further normative theorization. By exploring available definitions and how marginalization appears in bioethical literature, recurring patterns and conceptual gaps are identified. The analysis reveals two major findings. First, while definitions from disciplines beyond bioethics provide valuable insights, marginalization has not been normatively theorized as a distinct conceptual phenomenon within bioethics. Instead, dynamics of marginalization are largely addressed through established bioethical concepts, such as vulnerability or epistemic injustice. Second, it stands out that the contemporary redefinition of vulnerability in bioethics increasingly incorporates discussions on systemic exclusion and structural injustice, both central to marginalization. This raises the question of whether marginalization requires distinct conceptualization in bioethics or if its core dimensions are already encompassed by existing approaches and concepts. Consequently, this paper argues that further conceptual debate on marginalization is needed to assess its potentially distinct contributions to bioethics. It develops arguments for making space for the concept of marginalization within bioethics in its own right. To address these conceptual gaps, this paper calls for a more explicit normative analysis of marginalization to establish its role in bioethical discourse and to clarify its implications for equitable health, healthcare practices, and policies.\n"]