While most executive agencies have a single director, administrator, or secretary appointed by the president of the United States, independent agencies (in the narrower sense of being outside presidential control) almost always have a commission, board, or similar collegial body consisting of five to seven members who share power over the agency. (This is why many independent agencies include the word "Commission" or "Board" in their name.) The president appoints the commissioners or board members, subject to Senate confirmation, but they often serve terms that are staggered and longer than a four-year presidential term, meaning that most presidents will not have the opportunity to appoint all the commissioners of a given independent agency. In addition, most independent agencies have a statutory requirement of bipartisan membership on the commission, so the president cannot simply fill vacancies with members of his own political party. The president can normally designate which commissioner will serve as the chairperson.