(a) This section applies only to an individual who on or after July 1, 2011, becomes a member of:

(1) the Employees’ Pension System;

(2) the Law Enforcement Officers’ Pension System; or

(3) the Teachers’ Pension System.

(b) (1) In this subsection, “break in service” means a period of employment in which the member’s employer did not:

(i) deduct the member contributions from the compensation of the member; or

(ii) report the hours worked by the member.

(2) (i) For the purpose of computing benefits under this Division II, the average final compensation of a member equals the average annual earnable compensation of the member, adjusted as provided in this section, during the 5 consecutive years that provide the highest average earnable compensation.

(ii) If the member experienced any break in service during the 5 consecutive years that provide the member’s highest average earnable compensation, the Board of Trustees:

1. may not include in the computation of average final compensation the period of months of the breaks in service that otherwise would be included in the computation; and

2. in order to generate the highest average earnable compensation for the member, shall extend the 5-year period by an equal number of months immediately preceding or following that period.

(c) (1) This subsection applies to a member whose eligibility service has been adjusted under this Division II to compute creditable service, on the basis of the member having completed less than the normal hours of service for the member’s position.

(2) A member’s earnable compensation shall be adjusted to a full-time basis for any period included in the computation of average final compensation.

(d) Except for a salary increase because of a member’s promotion, the member’s average final compensation does not include a salary increase in the last 5 years of employment if it is an extraordinary salary increase according to regulations that the Board of Trustees adopts.