This paper takes stock of the most recent scholarship on symbolic boundaries and how these interact with social boundaries - more durable and institutionalized social differences. Our primary goal is to raise awareness of a growing body of empirical work, and to highlight key mechanisms which they address, among them: the strategic management of collective identities, cultural classification, the construction of authenticity, moral boundary maintenance, and genre-crossing. We introduce the articles included in this issue and discuss how ethno-racial boundaries intersect with class, immigration, and nationhood. We also describe new work on aesthetic boundaries, as well as recent efforts pertaining to gender, sexuality, the workplace, and religion. We close with a discussion of promising research on health, risk, and policy. We hope to demonstrate some of the intellectual rewards of interdisciplinary engagement, and encourage others to more systematically contribute to analyzing fundamental boundary processes.