40 ILCS 5/7-208
One earnings and experience variation reserve shall be maintained. All other accounts for this purpose shall be abolished upon the effective date of this amendatory Act of 1995. Moneys in abolished reserve accounts shall be transferred to the earnings and experience variation reserve. No more than one-half of all interest income and earnings on investments of whatever type, including realized gains on disposition of investments and unrealized gains in market value, shall be credited thereto. All investment earnings expense of whatever type, including realized losses on disposition of investments and unrealized losses in market value, shall be charged thereto. All administrative expenses directly relating to investments may be charged thereto. Excess or deficiencies in the annuity and disability reserves shall be charged or credited to this reserve. Whenever a balance exists in such reserve, it shall be included in the basis used for determining the effective interest rate. The balance in the reserve shall be distributed as of the end of each year, but a contingency balance of not more than twice the projected interest requirement for the next year may be maintained. If the balance ever exceeds twice the projected requirement, the excess shall be distributed to municipality reserves.
If the Board determines that the funds available in this reserve, after required transfers, will not be sufficient to provide administrative expenses of the fund, the Board may include in the municipality contribution rate authorized by Section 7-172 a percentage of earnings on the earnings of all participating employees to provide an amount required for the administrative expenses.
Upon adoption of generally accepted accounting procedures that allow for the recognition of unrealized gains or losses in market value, those gains or losses shall be allocated to employer accounts including the earnings and experience variation reserve in the same proportion those accounts were to total assets prior to the implementation of market value accounting.
40 ILCS 5/7-208