40 ILCS 5/3-144
As of July 20, 1949, the pension fund established under this Article superseded and replaced any annuity and benefit fund in operation under "An Act to provide for the creation, setting apart, maintenance and administration of a policemen's annuity and benefit fund in cities having a population of not less than one hundred thousand and not more than two hundred thousand inhabitants", approved June 12, 1931, as amended, which Act was repealed in 1949. Any such superseded fund was merged into and became a part of the pension fund established under this Article.
All annuities, pensions and other benefits granted under any such superseded fund or any pre-existing police pension fund, and claims pending under such funds which were approved by the board of the superseding funds shall be paid by the board of trustees of the funds established under this Article according to the law under which the annuities, pensions or other benefits were granted.
40 ILCS 5/3-144