40 ILCS 5/2-127
The system shall be administered by a board of trustees of 7 members as follows: 3 members of the Senate appointed by the President; 3 members of the House of Representatives appointed by the Speaker; and one person elected from the member annuitants under rules prescribed by the board. Only participants are eligible to serve as board members. Not more than 2 members of the House of Representatives, and not more than 2 members of the Senate so appointed shall be of the same political party. Appointed board members shall serve for 2-year terms. If the office of President of the Senate or Speaker of the House is vacant or its incumbent is not a participant, the position of trustee otherwise occupied by such officers shall be deemed vacant and be filled by appointment by the Governor with a member of the Senate or the House, as the case may be. This appointment shall be of the same political party as the vacated position.
Elections for the annuitant member shall be held in January of 1993 and every fourth year thereafter. Nominations and elections shall be conducted in accordance with such procedures as the Board may prescribe. In the event that only one eligible person is nominated, the Board may declare the nominee elected at the close of the nomination period, and need not conduct an election. The annuitant member elected in 1989 shall serve for a term of 4 years beginning February 1, 1989; thereafter, an annuitant member shall serve for a period of 4 years from the February 1st immediately following the date of election, and until a successor is elected and qualified.
Every person designated to serve as a trustee shall take an oath of office and shall thereupon qualify as a trustee. The oath shall state that the person will diligently and honestly administer the affairs of the system, and will not knowingly violate or wilfully permit the violation of any of the provisions of this Article.
40 ILCS 5/2-127