The provisions of the retirement system established by R.S. 11:401 may be amended by action of the legislature, in the same manner as any other statute may be amended by the legislature. In addition, action of the board with respect to the payment of cost-of-living adjustments, as provided in R.S. 11:491, and with respect to the payment of employee contributions, as provided in R.S. 11:154 shall be considered amendments to the provisions of the retirement system.
La. Consolidated Public Retirement § 11:406