Mo. Rev. Stat. § 168.112
Current with changes from the 2023 Legislative Session
An indefinite contract between a permanent teacher and a board of education may be terminated or modified at any time by the mutual consent of the parties thereto. Any teacher who desires to terminate his contract at the end of a school term shall give written notice of his intention to do so and the reasons therefor not later than June first of the year in which the term ends.
§ 168.112, RSMo