40 ILCS 5/18-123
A participant in active service as a judge after July 26, 1949, is eligible to participate in the survivor's annuity provided under this Article. A married participant who was in service on July 27, 1949 is subject to the provisions relating to survivor's annuities unless he or she filed with the Board written notice not to participate in such annuity within 30 days of that date.
A married judge who becomes a participant after July 27, 1949, an unmarried judge who becomes a participant after December 31, 1992, and a judge who marries after becoming a participant shall be subject to the provisions relating to survivor's annuities unless he or she files with the Board written notice of his or her election not to participate in the survivor's annuity within 30 days of the date of being notified of the option by the System. Once the election period has expired, a judge may not withdraw from participation under this Section except as provided in Section 18-129.
A person who became a participant before January 1, 1997 and who is not contributing for survivor's annuity may elect to make contributions for survivor's annuity by filing written notice of the election with the Board no later than April 1, 1998. Such an election may not be rescinded. A person who has so elected shall be entitled only to partial credit for survivor's annuity under subsection (g) of Section 18-129 unless all of the payments required under subsection (f) of that Section have been made.
A married participant who elects not to participate in the survivor's annuity provisions shall thereafter be ineligible to participate in the survivor's annuity unless the election is rescinded as provided herein.
A married participant who elected not to participate in the survivor's annuity provisions and who is still a judge, may elect to participate therein by filing with the Board before April 1, 1998 a written recision of the election not to participate. The participant and his or her spouse shall be entitled to all the rights of the survivor's annuity, except as limited in Section 18-129, upon paying the System for the survivor's annuity 1 1/2% of each payment of salary earned between July 27, 1949 and July 12, 1953, and 2 1/2% of each payment of salary earned after July 12, 1953, together with interest at 4% per annum, compounded annually from the date the contributions would have been due to the date of payment. The time and manner of paying the required contributions and interest shall be prescribed by the Board.
40 ILCS 5/18-123