Section 40 ILCS 5/4-107 - Qualifications(a) A firefighter who has not contributed to the fund during the entire period of service, to be entitled to the benefits of this Article, must contribute to the fund the amount he or she would have paid had deductions been made from his or her salary during the entire period of his or her creditable service.(b) Any person appointed as a firefighter in a municipality shall, within 3 months after receiving his or her first appointment and within 3 months after any reappointment make written application to the board to come under the provisions of this Article.(c) A person otherwise qualified to participate who was excluded from participation by reason of the age or fitness requirements removed by this amendatory Act of 1995 may elect to participate by making a written application to the Board before July 1, 1996. Persons so electing shall begin participation on the first day of the month following the month in which the application is received by the Board. These persons may also elect to establish creditable service for periods of employment as a firefighter during which they did not participate by paying into the pension fund, before January 1, 1997, the amount that the person would have contributed had deductions from salary been made for this purpose at the time the service was rendered, together with interest thereon at 6% per annum, compounded annually, from the time the service was rendered until the date of payment.(d) A person described in subsection (h) of Section 15-107 shall not participate in any pension fund established under this Article with respect to employment for which he or she is a participating employee in the State Universities Retirement System.P.A. 89-52, eff. 6/30/1995; 90-576, eff. 3/31/1998.