With the popularity of social media, researchers and designers must consider a wide variety of privacy concerns while optimizing for meaningful social interactions and connection. While much of the privacy literature has focused on information disclosures, the interpersonal dynamics associated with being on social media make it important for us to look beyond informational privacy concerns to view privacy as a form of interpersonal boundary regulation. In other words, attaining the right level of privacy on social media is a process of negotiating how much, how little, or when we desire to interact with others, as well as the types of information we choose to share with them or allow them to share about us. We propose a framework for how researchers and practitioners can think about privacy as a form of interpersonal boundary regulation on social media by introducing five boundary types (i.e., relational, network, territorial, disclosure, and interactional) social media users manage. We conclude by providing tools for assessing privacy concerns in social media, as well as noting several challenges that must be overcome to help people to engage more fully and stay on social media.