Any public employer that is a participating unit of the system established under chapter 3-12C may become a participating unit under this chapter at any time on or after July 1, 2004. The decision to become a participating unit shall be made by the elected official, the appointed official, or the governing body in charge of the unit. The unit shall become a participating unit as soon as notice of the decision has been delivered in writing to the system. A participating unit at a later date may choose to rescind such status and may do so by delivering written notice of the decision to the system. However, if such a rescission occurs, the rescission does not affect the status of any participant who was employed by that unit.
SDCL 3-13A-18