Illinois Compiled Statutes
Pensions
Illinois Pension Code
40 ILCS 5/

1. The following persons shall not be eligible to participate in a fund created under this Article:
   1. part-time police officers, special police officers, night watchmen, temporary employees, traffic guards or so-called auxiliary police officers specially appointed to aid or direct traffic at or near schools or public functions, or to aid in civil defense, municipal parking lot attendants, clerks or other civilian employees of a police department who perform clerical duties exclusively;
   2. any police officer who fails to pay the contributions required under Section 3-125.1, computed (i) for funds established prior to August 5, 1963, from the date the municipality established the fund or the date of a police officer's first appointment (including an appointment on probation), whichever is later, or (ii) for funds established after August 5, 1963, from the date, as determined from the statistics or census provided in Section 3-103, the municipality became subject to this Article by attaining the minimum population or by referendum, or the date of a police officer's first appointment (including an appointment on probation), whichever is later, and continuing during his or her entire service as a police officer; and
   3. any person who has elected under Section 3-109.1 to participate in the Illinois Municipal Retirement Fund rather than in a fund established under this Article, without regard to whether the person continues to be employed as chief of police or is employed in some other rank or capacity within the police department, unless the person has lawfully rescinded that election.
2. A police officer who is reappointed shall, before being declared eligible to participate in the pension fund, repay to the fund as required by Section 3-124 any refund received there under.
3. Any person otherwise qualified to participate who was excluded from participation by reason of the age restriction removed by Public Act 79-1165 may elect to participate by making a written application to the Board before January 1, 1990. Persons so electing shall begin participation on the first day of the month following the date of application. Such persons may also elect to establish creditable service for periods of employment as a police officer during which they did not participate by paying into the police pension fund, before January 1, 1990, the amount that the person would have contributed had deductions from salary been made for such purpose at the time such service was rendered, together with interest thereon at 6% per annum from the time such service was rendered until the date the payment is made.
4. A person otherwise qualified to participate who was excluded from participation by reason of the fitness requirement 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 police officer during which they did not participate by paying into the police 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.

1. 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.
2. 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.