(40 ILCS 5/13-304.1)
    Sec. 13-304.1. Optional plan of additional benefits and contributions made January 1, 2003 through December 31, 2007.
    (a) While this plan is in effect, an employee may establish optional additional credit toward additional benefits for eligible service by making an irrevocable written election to make additional contributions as authorized in this Section. An employee may begin to make additional contributions under this Section, via payroll deduction, no earlier than the first pay period of the calendar year in which the employee fulfills the 10-year service requirement described in subsection (g). The additional contributions of 4% of salary shall be paid to the Fund on the same basis and under the same conditions as contributions required under Section 13-502.
    (b) For service before an irrevocable option is elected, but within the same calendar year, an additional contribution may be made of 4% of the salary for the applicable period of service, plus interest from the date of service to the date of contribution at a rate equal to the higher of 8% per annum or the actuarial investment return assumption used in the Fund's most recent annual actuarial statement. All payments for past service must be paid within the calendar year in which the service was earned; except that a person who has withdrawn from service and is eligible for a retirement annuity under Section 13-301 may pay the additional contribution for past service within the calendar year of withdrawal within the 30 days after withdrawal from service, as long as payment is made in full before the retirement annuity commences and before December 31, 2007. Nothing in this Section may be construed to allow an additional optional contribution to be made on the account of a deceased employee.
    (c) The maximum additional benefit for current service for which an employee may make contributions under this Section in a single year is limited to one year of service in each of 2003, 2004, 2005, 2006, and 2007. The total additional benefit that may be accumulated under this Section, including any additional benefit accumulated under a prior optional benefit plan, is 12% of average final salary at retirement.
    The additional benefit shall accrue for all periods of eligible service for which additional contributions have been paid in full in accordance with this Section, subject to the applicable limitations on maximum annuity.
    The additional benefit shall consist of an additional 1% of average final salary for each year of service for which optional contributions have been paid, to be added to the employee's retirement annuity as otherwise computed under this Article. The calculation of these additional benefits shall be subject to the same terms and conditions as are used in the calculation of the retirement annuity under this Article. The additional benefit shall be included in the calculation of the automatic annual increase in annuity under Section 13-302(d) and in the calculation of surviving spouse's annuity, where applicable. However, no additional benefit may be granted which produces a total annuity greater than the applicable maximum established for that type of annuity in this Article.
    (d) Refunds of additional optional contributions made in accordance with the provisions and limitations of this Section shall be made on the same basis and under the same conditions as are provided under Section 13-601. Any refund of contributions that exceed the limits specified in this Section shall be made in accordance with established Fund policy.
    (e) The additional contributions shall be accounted for in a separate Optional Contribution Reserve.
    (f) The tax levy computed under Section 13-503 shall be based on employee contributions and the amount of optional additional employee contributions, as provided in that Section.
    (g) The service eligible for optional additional contributions under this Section is limited to service as an employee as defined in Section 13-204, and subject to Sections 13-401 and 13-402, but excluding service credited under subsections 13-401(a)4 and 13-401(d). Service granted under Section 13-801 or 13-802 is not eligible for optional additional contributions. Eligible service is further limited to service rendered during or after the calendar year in which the employee reaches 10 years of service as defined under Section 13-402, exclusive of any credit under Article 20.
    Service eligible for optional additional contributions under this Section includes any period of disability paid from this Fund that would have been eligible service if the employee were in active service rather than disabled. The additional contributions for a period of disability shall be calculated as 4% of the salary that the employee would have received if he or she had been in active service during the applicable period of disability, plus interest at a rate equal to the higher of 8% per annum or the actuarial investment return assumption used in the Fund's most recent annual actuarial statement, compounded annually, from the date of the service to the date of payment. The contribution must be paid to the Fund no later than 3 months after the employee returns to service from disability, and in any event prior to December 31, 2007.
    (h) The minimum period for which an employee may make an irrevocable election to make additional contributions shall be 26 consecutive pay periods, unless the employee first accumulates the maximum optional credit as described in subsection (c) of this Section. The maximum period for which an employee may make irrevocable elections for additional contributions shall be from the date of election through the last pay period eligible for contributions under this Section.
    (i) This plan of additional benefits and contributions expires on December 31, 2007. No additional contributions may be made after that date, and no additional benefits will accrue after that date.
(Source: P.A. 92-599, eff. 6-28-02.)