The organisational literature has overlooked the diversity of change agents’ psychological ownership experiences in the context of major (or second-order) change. The present study examined the psychological ownership of change agents while assimilating a second-order change in schools, specifically how psychological ownership is experienced, its components, and how it is perceived as guiding the agents’ actions. The study used the case study method and focused on six Israeli state-religious schools, which adopted a new liberal curriculum. Thirty-one semi-structured interviews were conducted with six principals and 25 teachers (middle-level managers and educators). Analysis of the findings revealed the types of psychological ownership that change agents experience (ownership by process, by interest, and by means); two main components of the agents’ psychological ownership (accountability and territoriality); and three perceived types of sharing associated with ownership (active, passive, and defensive). The implications of the findings are discussed.