Mo. Rev. Stat. § 210.924
The department and the department of social services shall promulgate rules and regulations necessary to implement the provisions of sections 210.900 to 210.936. Any rule or portion of a rule, as that term is defined in section 536.010, that is created under the authority delegated in sections 210.900 to 210.936 shall become effective only if it complies with and is subject to all of the provisions of chapter 536 and, if applicable, section 536.028. All rulemaking authority delegated prior to August 28, 1999, is of no force and effect and repealed. Nothing in this section shall be interpreted to repeal or affect the validity of any rule filed or adopted prior to August 28, 1999, if it fully complied with all applicable provisions of law. This section and chapter 536 are nonseverable and if any of the powers vested with the general assembly pursuant to chapter 536 to review, to delay the effective date or to disapprove and annul a rule are subsequently held unconstitutional, then the grant of rulemaking authority and any rule proposed or adopted after August 28, 1999, shall be invalid and void.
§ 210.924, RSMo