Illinois Statutes Chapter 40. Pensions § 5/3-109.1. Chief of police

(a) Except as provided in subsection (a-5), beginning January 1, 1990, any person who is employed as the chief of police of a “participating municipality” as defined in Section 7-106 of this Code, may elect to participate in the Illinois Municipal Retirement Fund rather than in a fund created under this Article 3. Except as provided in subsection (b), this election shall be irrevocable, and shall be filed in writing with the Board of the Illinois Municipal Retirement Fund.

(a-5) On or after January 1, 2019, a person may not elect to participate in the Illinois Municipal Retirement Fund with respect to his or her employment as the chief of police of a participating municipality, unless that person became a participating employee in the Illinois Municipal Retirement Fund before January 1, 2019.

(b) Until January 1, 1999, a chief of police who has elected under this Section to participate in IMRF rather than a fund created under this Article may elect to rescind that election and transfer his or her participation to the police pension fund established under this Article by the employing municipality. The chief must notify the boards of trustees of both funds in writing of his or her decision to rescind the election and transfer participation. A chief of police who transfers participation under this subsection (b) shall not be deemed ineligible to participate in the police pension fund by reason of having failed to apply within the 3-month period specified in Section 3-106.