This paper discusses a qualitative participatory action research study, which examined the nature of the cohort learning experience in an online master's program, from both faculty and student perspectives. After describing this online master's program in adult education designed from a social constructivist theoretical frame, this paper discusses two primary areas of findings related to cohort learning. First, were those related to the ongoing negotiation of the learning process: the importance of an opening residential; a consistent but flexible cohort structure; and building ongoing relationships. Second, were those related to the ongoing construction of knowledge: the role of team-teaching and the cohort model in transformative learning; the application of theory to real life practice, and the value of group support and collaboration in conducting research and constructing knowledge. Implications for practice are discussed.