(a) “Compensation earnable” means the sum of the following:
(1) The average annualized pay rate, which shall be determined as the quotient obtained when salary or wages, as described in Section 22119.2 or 22119.3, paid in a school year is divided by the service credited for that school year. The quotient shall not exceed the member’s highest annualized pay rate for that school year.
(2) Remuneration that is paid in addition to salary or wages, as described in Section 22119.2 or 22119.3, for the school year described in paragraph (1).
(b) If a member earns creditable compensation at multiple annualized pay rates during a school year and service credited at the highest annualized pay rate is at least 0.900 of a year, compensation earnable shall be determined as if all service credited for that year had been earned at the highest annualized pay rate.
(c) Compensation earnable excludes creditable compensation for which contributions are credited by the system to the Defined Benefit Supplement Program.