Section 40 ILCS 5/15-135.1 - Election to avoid application of P.A. 90-65(a) A participant who was an employee on July 7, 1997 and retires on or after the effective date of this amendatory Act of the 91st General Assembly may elect in writing at the time of retirement to have the retirement annuity calculated in accordance with the provisions of Sections 15-135 and 15-136 as they existed immediately prior to amendment by Public Act 90-65. This election, once made, is irrevocable.(b) The fact that a person has elected to participate in the optional retirement program under Section 15-158.2 or has elected the portability option under subsection (a-1) of Section 15-154 does not prevent the person from making an election under subsection (a) of this Section; the fact that such a person makes an election under subsection (a) does not allow the person to change the irrevocable election that he or she made under Section 15-158.2 or subsection (a-1) of Section 15-154.(c) The System shall promptly notify the Department of Central Management Services of each election made under this Section. P.A. 91-395, eff. 7/30/1999.