Recent literature has added another dimension to the well‐documented patterns of social class inequality in education: academic undermatch. Undermatch (which occurs when students attend institutions of lower selectivity than they are academically qualified to attend) is both widespread and unequal, with students from less advantaged families more likely to undermatch. Although proliferating, the research on undermatch has focused primarily on documenting the extent of, and less on exploring the mechanisms underlying, undermatch. Moreover, this literature has developed largely independent of the sociological research on cultural capital. Therefore, when scholars consider underlying mechanisms, they often focus narrowly on college‐specific information, without considering the broader cultural context in which students are embedded. Drawing on the literature on undermatch, as well as the sociological research on cultural capital, I differentiate between general and specific cultural capital. Moreover, instead of simply estimating whether students undermatch or not, I consider different types of undermatch. Results from the Educational Longitudinal Survey reveal that the effects of cultural capital are indeed heterogeneous, both with respect to its relationship to undermatch and its contribution to social class inequality. Findings have important implications for understanding undermatch and the role of cultural capital in reducing and reproducing social inequality.