Mo. Rev. Stat. § 70.646

70.646. Alternate election, system may provide for, how. — 1. Each political subdivision may, by majority vote of its governing body, elect from time to time, with respect to its members retiring in the future, to provide an alternate for unreduced age and service retirement eligibility for its members, which alternate shall allow for unreduced age and service retirement for its members who have years of attained age and years of credited service in force which total eighty or more. If a political subdivision makes no election under this section, the minimum age and service requirements of section 70.645 shall be in effect. The clerk or secretary of the political subdivision shall certify an election concerning age and service eligibility to the board within ten days after such vote. The effective date of the political subdivision's age and service eligibility election is the first day of the calendar month specified by such governing body, or the first day of the calendar month next following receipt by the board of the certification of the age and service eligibility election, or the effective date of the political subdivision's becoming an employer, whichever is the latest date. Such age and service eligibility may be changed from time to time by a majority vote of the governing body, but not more than once in two years. If such election is to adopt the alternate age and service eligibility provided for in this section, such alternate provisions shall be applicable to allowances for which the employer is financially responsible for all of the employer's employees who accrue credited service with the employer while such alternate is in effect. If the election is to limit retirement eligibility to the minimum eligibility provisions of section 70.645 , such election shall be applicable to employees of the employer who did not accrue service credit with the employer while the alternate may have been in effect.

2. Should an employer change its age and service eligibility election as provided in this section, the employer contributions shall be correspondingly changed effective the same date as the age and service eligibility change.

3. The limitation on increases in an employer's contributions provided by subsection 6 of section 70.730 shall not apply to any contribution increase resulting from an employer's making an age and service eligibility election under the provisions of this section.

(L. 1988 H.B. 1098, A.L. 1992 H.B. 1440)