Mo. Rev. Stat. § 56.833

56.833. Deferred benefits allowed, when — forfeiture of creditable service, when, restoration of service, how — illness or injury, counts as service. — 1. Upon termination of employment, any person who became a member prior to January 1, 2019, shall be entitled to a deferred normal annuity, payable at age fifty-five with twelve or more years of creditable service as determined in subsection 3 of section 56.840 . Upon termination of employment, any person who became a member on or after January 1, 2019, shall be entitled to a deferred normal annuity, payable at age sixty with twelve or more years of creditable service as determined in subsection 3 of section 56.840 . Any member with less than twelve years of creditable service shall forfeit all rights in the fund, including the member's accrued creditable service as of the date of the member's termination of employment.

2. A former member who has forfeited creditable service may have the creditable service restored by again becoming an employee within ten years of the date of the termination of employment, by completing four years of continuous membership service, and by contributing an amount to the fund equal to any lump sum payment received under subsections 11 and 12 of section 56.807 . Notwithstanding any other provision of section 104.800 to the contrary, a former member shall not be entitled to transfer creditable service into this retirement system unless the member previously vested in this system.

3. Absences for sickness or injury of less than twelve months shall be counted as membership service.

(L. 1989 S.B. 30 § 56.850 , A.L. 2018 H.B. 1291 merged with S.B. 892)