(40 ILCS 5/17-119.1)
    Sec. 17-119.1. Optional increase in retirement annuity.
    (a) A member of the Fund may qualify for the augmented rate under subdivision (b)(3) of Section 17-116 for all years of creditable service earned before July 1, 1998 by making the optional contribution specified in subsection (b); except that a member who retires on or after July 1, 1998 with at least 30 years of creditable service at retirement qualifies for the augmented rate without making any contribution under subsection (b). Any member who retires on or after July 1, 1998 and before the effective date of this amendatory Act of the 92nd General Assembly with at least 30 years of creditable service shall be paid a lump sum equal to the amount he or she would have received under the augmented rate minus the amount he or she actually received. A member may not elect to qualify for the augmented rate for only a portion of his or her creditable service earned before July 1, 1998.
    (b) The contribution shall be an amount equal to 1.0% of the member's highest salary rate in the 4 consecutive school years immediately prior to but not including the school year in which the application occurs, multiplied by the number of years of creditable service earned by the member before July 1, 1998 or 20, whichever is less. This contribution shall be reduced by 1.0% of that salary rate for every 3 full years of creditable service earned by the member after June 30, 1998. The contribution shall be further reduced at the rate of 25% of the contribution (as reduced for service after June 30, 1998) for each year of the member's total creditable service in excess of 34 years. The contribution shall not in any event exceed 20% of that salary rate.
    The member shall pay to the Fund the amount of the contribution as calculated at the time of application under this Section. The amount of the contribution determined under this subsection shall be recalculated at the time of retirement, and if the Fund determines that the amount paid by the member exceeds the recalculated amount, the Fund shall refund the difference to the member with regular interest from the date of payment to the date of refund.
    The contribution required by this subsection shall be paid in one of the following ways or in a combination of the following ways that does not extend over more than 5 years:
        (i) in a lump sum on or before the date of retirement;
        (ii) in substantially equal installments over a
    
period of time not to exceed 5 years, as a deduction from salary in accordance with Section 17-130.2;
        (iii) in substantially equal monthly installments
    
over a 24-month period, by a deduction from the annuitant's monthly benefit.
    (c) If the member fails to make the full contribution under this Section in a timely fashion, the payments made under this Section shall be refunded to the member, without interest. If the member (including a member who has become an annuitant) dies before making the full contribution, the payments made under this Section shall be refunded to the member's designated beneficiary if there is no survivor's or children's pension benefit payable. If there is a survivor's or children's benefit payable, then all payments made under this Section shall be retained by the Fund and all such survivor's or children's benefits payable shall be calculated as if all contributions required under this Section have been paid in full.
    (d) For purposes of this Section and subsection (b) of Section 17-116, optional creditable service established by a member shall be deemed to have been earned at the time of the employment or other qualifying event upon which the service is based, rather than at the time the credit was established in this Fund.
    (e) The contributions required under this Section are the responsibility of the teacher and not the teacher's employer. However, an employer of teachers may, after the effective date of this amendatory Act of 1998, specifically agree, through collective bargaining or otherwise, to make the contributions required by this Section on behalf of those teachers.
(Source: P.A. 91-17, eff. 6-4-99; 92-416, eff. 8-17-01; 92-599, eff. 6-28-02; 92-651, eff. 7-11-02.)