The Cistercian monastic congregations are immediate members of the Order, not the individual monasteries, except for art. 8, nor individual monks. Therefore, individual monks through their monastery belong to their own Congregation and through their own Congregation belong to the Order. (Constitutions of the Order, art. 7)
Cistercian monastic congregations are unions of several monasteries sui juris subject to the authority of the Chapter of the Congregation and of the same superior, who is called President. (Constitutions of the Order, art. 15)