; and (B) may not continue to serve after the end of the session of the Congress during which the term of the commissioner expires. (3) Acting commissioner (A) In general If a vacancy exists more than 90 days after the date on which the President first submits to the Senate a nomination of a person to fill a vacancy on the Commission, the President may appoint an acting commissioner to serve on the Commission until the vacancy is filled, subject to subparagraph (B). (B) Maximum term An acting commissioner appointed under subparagraph (A) may serve on the Commission for not more than 210 days. (e) Employment A commissioner may not engage in any other business, vocation, or employment while serving on the Commission. (f) Chairperson (1) Designation The President shall designate 1 commissioner to serve as the chairperson of the Commission. (2) Duties The chairperson of the Commission shall oversee the executive and administrative operations of the Commission, including functions of the Commission with respect to— (A) the appointment and employment of hearing examiners in accordance with the provisions of title 5, United States Code; (B) the selection, appointment, and fixing of the compensation of any personnel that the chairperson determines necessary, including an executive director; (C) the supervision of personnel employed by or assigned to the Commission, except that each commissioner may select and supervise personnel for the personal staff of that commissioner; (D) the distribution of business among personnel and among administrative units of the Commission