Education researchers have long wrestled with the interplay of oppressive structures and individual agency in reproducing, sustaining, and contesting marginalization. In this article, we suggest that Weis and Fine's construct of critical bifocality may assist researchers in understanding and addressing marginalization in mathematics education. We conduct a conceptual review of existing mathematics education literature that accounts for both structure and agency in theorizing marginalization. By reading this literature alongside Weis and Fine's 2012 article, we develop four criteria for operationalizing critical bifocality in mathematics education research. The findings from this review highlight the interconnectedness of structures and individual lives, of the material and ideological elements of marginalization, of intersectionality and within-group heterogeneity, and of histories and institutions. Additionally, they offer theoretical and methodological recommendations for researchers studying marginalization in mathematics education.