40 ILCS 5/9-167
In lieu of an annuity, an employee who withdraws after age 60, having annuity rights based on a credit of not more than 10 years of service, or an employee who withdraws and whose annuity would amount to less than $150 a month for life, or a former employee who is receiving an annuity from the Fund of less than $150 per month, regardless of his date of withdrawal from service, may elect to receive a refund of the total sum accumulated to his credit from employee contributions for annuity purposes, minus any amounts previously paid to him by the Fund.
The widow of any employee, eligible for annuity upon the death of her husband, whose annuity would amount to less than $150 a month for life, and any widow receiving an annuity of less than $150 per month, may, in lieu of a widow's annuity, elect to receive a refund of the accumulated contributions for annuity purposes, based on the amounts contributed by her deceased employee husband, but reduced by any amounts theretofore paid to either the widow or the employee in the form of an annuity or refund out of such accumulated contributions.
Accumulated contributions shall mean the amounts including interest credited thereon contributed by the employee for age and service and widow's annuity to the date of his withdrawal or death, whichever first occurs, including the accumulations from any amounts contributed for him as salary deductions while receiving duty disability benefits, and if not otherwise included any accumulations from sums contributed by him and applied to any pension fund superseded by this fund, and interest credited thereon in accordance with the other provisions of this Article.
The acceptance of such refund in lieu of widow's annuity, on the part of a widow, shall not deprive a child or children of the right to receive a child's annuity as provided for in Sections 9-154 and 9-155 of this Article, and neither shall the payment of child's annuity in the case of such refund to a widow reduce the amount herein set forth as refundable to such widow electing a refund in lieu of widow's annuity.
40 ILCS 5/9-167