Mo. Rev. Stat. § 105.675

When a political subdivision or instrumentality of the state is the legislative body responsible for making a substantial proposed change in benefits, a prepared statement regarding the cost of such change shall be prepared in accordance with section 105.665 and shall be made available for its consideration. Such statement of cost shall be available as public information for at least forty-five calendar days before the legislative body can take final action to adopt the substantial proposed change in benefits. The statement of cost required by this section shall be filed in the office of the clerk, secretary or other individual responsible for keeping the official records of the legislative body, and with the joint committee on public employee retirement.