This study investigated the experience of involuntary membership in U.S. and Norwegian prisons. The purpose of the study was two-fold: 1) offer a comprehensive understanding of the construct of membership, and 2) develop a substantive, mid-range theory of involuntary membership (Glaser & Strauss, 1967; Merton, 1968; Weick, 1974). The research questions posed were designed to clarify the experience of involuntary membership and included: What facets comprise involuntary membership?, In what ways do individuals describe the experience of involuntary membership?, and In what ways does Norwegian involuntary membership differ from U.S. involuntary membership in a prison setting? In order to answer these questions, I conducted 62 in-depth interviews in the United States and Norway with incarcerated individuals (n = 41), correctional officers (n = 10), wardens (n = 3), and prison teachers (n = 8). The interviews were dispersed across four separate prison facilities. I took a grounded theoretical approach to the data and used the constant comparative method in my analysis. Participants spoke about involuntary membership in relation to 10 distinct facets: Activities, Belongings, Body, Communication, Mind, Organizational Boundary Management, Space, Sound, Relationships, and Time. In addition, the participants in the study described their experience with involuntary membership in relation to their 1) responses to, and 2) outcomes of the phenomenon. Similarities and differences in the experience of involuntary membership between the United States and Norway were also discussed. The three-macro themes in this study came together to create a substantive, mid-range theory of involuntary membership in prisons. In order to explicate this theory, I offered a Process Model of Involuntary Membership and subsequently elucidated the theory using a structurational ontology (see Banks & Riley, 1993; Kirby & Krone, 2002) or worldview (Kilminster, 1991). This study contributes to communication research and theorizing by illuminating and addressing the limitations of previous scholarship. Theoretical implications and future research directions are also discussed. / text