Missouri Code of State Regulations
Title 12 - DEPARTMENT OF REVENUE
Division 10 - Director of Revenue
Chapter 24 - Driver License Bureau Rules
Section 12 CSR 10-24.190 - Driver License Retesting Requirements After a License, School Bus Permit or Temporary Instruction Permit Expires/Examination Results to be Invalid After (1) Year

(1) Every holder of a valid Missouri driver license, school bus permit, or temporary instruction permit shall renew that license or permit on or before the date of expiration. This license or permit can be renewed up to six (6) months (one hundred eighty-four (184 days) prior to the date of expiration.

(2) If a person does not renew a driver license, issued by this state or any other state, school bus permit, or temporary instruction permit, within one hundred eighty-four (184) days from the expiration date of the license or permit, the holder of such license or permit shall be required to complete all written and skills tests required to qualify for such license or permit as required pursuant to Chapter 302, RSMo. No license or permit is valid for operation of a motor vehicle beyond the date of expiration of the license or permit.

(3) If the end of the one hundred eighty-four (184)-day period falls on a legal holiday, Saturday or Sunday, the one hundred eighty-fourth day shall be deemed to fall on the next working day.

(4) Examinations for a driver license, school bus permit or temporary instruction permit shall remain valid unless retesting is required by Missouri law or for a period of one (1) year from the date the examination completion form was completed by the Missouri State Highway Patrol or a certified Commercial Driver License Third Party Tester, whichever occurs first. An applicant shall be re-examined prior to issuance of a driver license or instruction permit if the examinations have been completed more than one (1) year prior to the date of application for a driver license, school bus permit or temporary instruction permit.