The Union is governed by its General Assembly, which meets every three years. The Council is its top executive body, supervising the activities of the nineteen specialized International Commissions and the four Affiliated Commissions – it typically meets once or twice per year. The Union is composed of Members representing identified physics communities. At present 60 Members adhere to IUPAP. The Members are represented by Liaison Committees. Members of the Council and Commissions are elected by the General Assembly, based on nominations received from Liaison Committees and existing Council and Commission members.