Mo. Const. art. V, § 25(c)(1)

Each judge appointed pursuant to the provisions of sections 25(a)-(g) shall hold office for a term ending December thirty-first following the next general election after the expiration of twelve months in the office. Any judge holding office, or elected thereto, at the time of the election by which the provisions of sections 25(a)-(g) become applicable to his office, shall, unless removed for cause, remain in office for the term to which he would have been entitled had the provisions of sections 25(a)-(g) not become applicable to his office. Not less than sixty days prior to the holding of the general election next preceding the expiration of his term of office, any judge whose office is subject to the provisions of sections 25(a)-(g) may file in the office of the secretary of state a declaration of candidacy for election to succeed himself. If a declaration is not so filed by any judge, the vacancy resulting from the expiration of his term of office shall be filled by appointment as herein provided. If such declaration is filed, his name shall be submitted at said next general election to the voters eligible to vote within the state if his office is that of judge of the supreme court, or within the geographic jurisdiction limit of the district where he serves if his office is that of a judge of the court of appeals, or within the circuit if his office is that of circuit judge, or within the county if his office is that of associate circuit judge on a separate judicial ballot, without party designation, reading:

"Shall Judge __________________ (Here the name of the judge shall be inserted) of the __________________ (Here the title of the court shall be inserted) be retained in office? Yes ☐ No ☐ (Mark an "X" in the box you prefer.)"

If a majority of those voting on the question vote against retaining him in office, upon the expiration of his term of office, a vacancy shall exist which shall be filled by appointment as provided in section 25(a); otherwise, said judge shall, unless removed for cause, remain in office for the number of years after December thirty-first following such election as is provided for the full term of such office, and at the expiration of each such term shall be eligible for retention in office by election in the manner here prescribed.