Mo. Rev. Stat. § 95.553: Independent board employees, how handled (St. Louis City).

No employees of any independent public board or agency shall be covered by any plan adopted hereunder unless their inclusion shall be authorized by resolution or order of such board or agency; but any such city may terminate the coverage of the employees of any public board or agency or modify the scope of their coverage in the manner authorized by ordinance or by amendment thereto, notwithstanding the resolution or order of any independent board or agency.