40 ILCS 5/1-101.3: Party in interest.

A person is a "party in interest" with respect to a pension fund or retirement system established under this Code if the person is:

(1) a fiduciary, counsel, or employee of the pension fund or retirement system, or a relative of such a person;

(2) a person providing services to the pension fund or retirement system, or a relative of such a person;

(3) an employer, any of whose employees are covered by the pension fund or retirement system;

(4) an employee organization, any members of which are covered by the pension fund or retirement system; or

(5) an employee, officer, or director (or an individual having powers or responsibilities similar to those of an officer or director) of the pension fund or retirement system or of a person described under item (2), (3), or (4) of this Section.