(40 ILCS 5/7-156) (from Ch. 108 1/2, par. 7-156)
    Sec. 7-156. Surviving spouse annuities - amount.
    (a) The amount of surviving spouse annuity shall be:
    1. Upon the death of an employee annuitant or such person entitled, upon application, to a retirement annuity at date of death, (i) an amount equal to 1/2 of the retirement annuity which was or would have been payable exclusive of the amount so payable which was provided from additional credits, and disregarding any election made under paragraph (b) of Section 7-142, plus (ii) an annuity which could be provided at the then attained age of the surviving spouse and under actuarial tables then in effect, from the excess of the additional credits, (excluding any such credits used to create a reversionary annuity) used to provide the annuity granted pursuant to paragraph (a) (2) of Section 7-142 of this article over the total annuity payments made pursuant thereto.
    2. Upon the death of a participating employee on or after attainment of age 55, an amount equal to 1/2 of the retirement annuity which he could have had as of the date of death had he then retired and applied for annuity, exclusive of the portion thereof which could have been provided from additional credits, and disregarding paragraph (b) of Section 7-142, plus an amount equal to the annuity which could be provided from the total of his accumulated additional credits at date of death, on the basis of the attained age of the surviving spouse on such date.
    3. Upon the death of a participating employee before age 55, an amount equal to 1/2 of the retirement annuity which he could have had as of his attained age on the date of death, had he then retired and applied for annuity, and the provisions of this Article that no such annuity shall begin until the employee has attained at least age 55 were not applicable, exclusive of the portion thereof which could have been provided from additional credits and disregarding paragraph (b) of Section 7-142, plus an amount equal to the annuity which could be provided from the total of his accumulated additional credits at date of death, on the basis of the attained age of the surviving spouse on such date.
    In the case of the surviving spouse of a person who dies before the effective date of this amendatory Act of the 94th General Assembly, if the surviving spouse is more than 5 years younger than the deceased, that portion of the annuity which is not based on additional credits shall be reduced in the ratio of the value of a life annuity of $1 per year at an age of 5 years less than the attained age of the deceased, at the earlier of the date of the death or the date his retirement annuity begins, to the value of a life annuity of $1 per year at the attained age of the surviving spouse on such date, according to actuarial tables approved by the Board. This reduction does not apply to the surviving spouse of a person who dies on or after the effective date of this amendatory Act of the 94th General Assembly.
    In computing the amount of a surviving spouse annuity, incremental increases of retirement annuities to the date of death of the employee annuitant shall be considered.
    (b) Each surviving spouse annuity payable on January 1, 1988 shall be increased on that date by 3% of the original amount of the annuity. Each surviving spouse annuity that begins after January 1, 1988 shall be increased on the January 1 next occurring after the annuity begins, by an amount equal to (i) 3% of the original amount thereof if the deceased employee was receiving a retirement annuity at the time of his death; otherwise (ii) 0.167% of the original amount thereof for each complete month which has elapsed since the date the annuity began.
    On each January 1 after the date of the initial increase under this subsection, each surviving spouse annuity shall be increased by 3% of the originally granted amount of the annuity.
(Source: P.A. 94-712, eff. 6-1-06.)