The board may use investment earnings on Plan A, Plan B, and Plan C investments in excess of normal requirements as determined by actuarial valuation to provide an annual cost-of-living adjustment to recipients of benefits of the respective plan, aged sixty-two or over, who have been retired at least one year, in an amount not to exceed two and one-half percent for each year from the effective date of the benefit. Such cost-of-living adjustment shall be paid only when such excess funds are available and in such manner and amount as determined by the board. Any adjustments to benefits for cost-of-living changes made by formal action of the board of trustees as provided herein shall be considered amendments to the provisions of the retirement system, except that it shall not be considered an increase in benefits by reason of an amendment made after October 14, 1987, as described in R.S. 11:1930 and 1931. If made by formal action of the board of trustees, such changes must be disclosed to members of the retirement system.
La. Consolidated Public Retirement § 11:1937