Sec. 6.02. ELIGIBILITY FOR SERVICE RETIREMENT. (a) Any member shall be eligible for service retirement if the member has attained the age of 55 years and completed at least 20 years of creditable service with the city, or has completed 23 years of creditable service, excluding any military service established under Section 5.02 of this Act.

(b) Except as provided by Subsection (c) of this section, the age and length-of-service requirements for service retirement may be changed if the change:

(1) is approved by the board's actuary;

(2) is adopted by the board as a board rule;

(3) applies to all persons who are members on the effective date of the change and all persons who become members after the effective date of the change; and

(4) does not increase the requirements for a person who already is eligible for service retirement on the effective date of the change.

(c) Any member, irrespective of the number of years of creditable service, shall be eligible for service retirement after attaining the age of 62 years. No member shall be paid any benefits by the system so long as the member is employed by the city as a police officer or by the system as an employee of the system's administrative staff.