50 Ill. Adm. Code 4402.50
Retroactive Pay Increases
Section 4402
Section 4402.50 Retroactive
Pay Increases
a) Retroactive payments of compensation are treated as if they
were paid during the period for which the increase is computed. If an employee
retired after the effective date of the salary increase and is entitled to
receive retroactive payment of salary, the new salary becomes final salary
attached to the rank at the time of retirement and the salary on which the
service pension is computed.
b) Entitlement to retroactive pay is to be determined by the
contract or agreement which authorizes the salary increase.