Section 40 ILCS 5/5-209 - Deficiencies in reserves(a) Whenever the balance in the expense reserve, the prior service annuity reserve, the child's annuity reserve, the duty disability reserve or the ordinary disability reserve is not sufficient to provide for the expenses and annuities or benefits chargeable to such reserves, the amount required shall be transferred from the following named reserves in the order stated: City contribution reserve, prior service annuity reserve, salary deduction reserve. When any amount exists in such reserves in excess of that required to pay any expenses, or annuities or benefits chargeable to any of said reserves to which a transfer has been made, the excess shall be transferred from the reserve having such excess to the reserve from which any such sums have been transferred until the full sum previously transferred is returned. Interest on such transfers or retransfers at 4% per year shall be credited to the investment and interest reserve.(b) Whenever the balance in the expense reserve, the prior service annuity reserve, the child's annuity reserve, the duty disability reserve or the ordinary disability reserve is in excess of that required to pay any expenses, annuities or benefits chargeable to that reserve and any retransfer required under subsection (a), the treasurer of the Fund shall so advise the Board and the chairman of the committee on finance of the city council of the city, and the city council may by ordinance direct the treasurer of the Fund to transfer some or all of such excess from such reserve to any other reserve of the Fund, the balance of which is not sufficient to provide for the expenses, annuities or benefits chargeable thereto. No such transfer shall in any way decrease any contribution required to be made or picked up by the city under this Article.