Mo. Rev. Stat. § 54.265: County governing body may authorize additional compensation for county treasurer — maximum allowed (second class and certain first, third and fourth class counties).

1. In addition to the compensation otherwise authorized by the provisions of this chapter, the governing body of each county of the first class not having a charter form of government, and of each county of the second class may authorize additional compensation for the county treasurer, to be paid from county funds, but in no event shall the total compensation for that officer, including any additional compensation which may be authorized by the governing body, exceed twenty-four thousand dollars for treasurers in such first class counties, and twenty thousand dollars for treasurers in second class counties.

2. In addition to other compensation which may be authorized under this chapter, the county governing body may authorize additional compensation in an amount not to exceed five thousand dollars per annum for the county treasurer in all counties of the third and fourth class, except counties under township organization.