Mo. Rev. Stat. § 115.609
Current with changes from the 2023 Legislative Session
In each city not situated in a county and in each county which has over nine hundred thousand inhabitants, all members of the county or city committee shall be elected at the primary election immediately preceding each gubernatorial election and shall hold office until their successors are elected and qualified. In each other county, all members of the county committee shall be elected at each primary election and shall hold office until their successors are elected and qualified.
§ 115.609, RSMo
Effective 1-1-78