Mo. Rev. Stat. § 105.160
Whenever any official or employee of the state of Missouri, county or any municipal corporation of the state of Missouri shall authorize in writing, the commissioner of administration in case such person is a state officer or employee, or the disbursing officer of the county or municipal corporation in case such person is an officer or employee of a county or municipal corporation, to withhold a specified portion of his salary or compensation, for the purpose of purchasing United States series "E" savings bonds, said commissioner of administration or disbursing officer, as the case may be, may withhold such sum from the salary or compensation of such officer or employee for the period and in the amount stated in the authorization, and issue a warrant therefor payable to such officer or employee, to be endorsed by the commissioner of administration or his authorized agent in case the officer or employee is paid out of the state treasury, and endorsed by the disbursing agent of the county or municipal corporation in case the officer or employee is paid out of the county or municipal corporation treasury, each and every pay period until cancelled as provided in section 105.180.
§ 105.160, RSMo