110 ILCS 805/3-31
To provide for or participate in provisions for insurance protection and benefits for its employees and their dependents, including but not limited to retirement annuities, medical, surgical and hospital benefits, in such types and amounts as shall be determined by the board for the purpose of aiding in securing and retaining the services of competent employees. Such insurance may include provisions for employees and their dependents who rely on treatment by spiritual means alone through prayer for healing in accord with the tenets and practices of well-recognized religious denominations. Where employee participation in such provisions is involved, the board may with the consent of the employee withhold deductions from the employee's salary necessary to defray the employee's share of such insurance cost.
For purposes of this section, the term "dependent" means an employee's spouse and any unmarried child (1) under the age of 19 years including (a) an adopted child and (b) a step-child or recognized child who lives with the employee in a regular parent-child relationship, or (2) under the age of 23 who is enrolled as a fulltime student in any accredited school, college or university.
110 ILCS 805/3-31