Mo. Rev. Stat. § 138.432
A complainant, respondent-assessor, or other party subject to a decision and order of a hearing officer, may file with the commission, within thirty days following the date of notification or mailing of such decision and order, an application to have such decision and order reviewed by the commission. Such application shall contain specific detailed grounds upon which it is claimed the decision is erroneous. The commission may summarily allow or deny an application for review. If an application is allowed, the commission may affirm, modify, reverse, or set aside the decision and order of the hearing officer on the basis of the evidence previously submitted in such case, may take additional evidence, or may remand the matter to the hearing officer with directions. Any additional hearing shall be conducted in accordance with the requirements of subsection 3 of section 138.431. The commission shall promptly notify the parties of its decision and order, together with its findings of fact and conclusions of law. The decision of the commission shall be subject to judicial review in the manner provided by subsection 4 of section 138.470. If an application for review is denied, the decision and order of the hearing officer shall be deemed to be the final decision of the commission for the purpose of judicial review and shall be subject to the judicial review within the time and in the manner provided for with respect to decisions of the commission pursuant to subsection 4 of section 138.470; except that, the time limitations shall run from the date of notice or mailing of the order of the commission denying the application for review.
§ 138.432, RSMo