40 ILCS 5/1-140
Every pension fund or retirement system under this Code, except for a pension fund established under Article 3 or 4 of this Code, shall develop and implement, by no later than June 30, 2017, a process to identify annuitants who are deceased. The process shall require the pension fund or retirement system to check for any deceased annuitants at least once per month and shall include the use of any commonly used methods to identify persons who are deceased, which include, but are not limited to, the use of a third party entity that specializes in the identification of deceased persons, the use of data provided by the Social Security Administration, the use of data provided by the Department of Public Health's Office of Vital Records, or the use of any other method that is commonly used by other states to identify deceased persons.
40 ILCS 5/1-140