Mo. Rev. Stat. § 103.133: Withdrawal from plan — participating agencies and political subdivisions, procedure — termination of plan effective, when.

A participating member agency may elect to withdraw from the plan by certifying such election of its governing body to the board. Such certification must be received by the board at least ninety days prior to the end of the then current plan year and termination of the agency's coverage under the plan will become effective at the end of the then current plan year.