Mo. Rev. Stat. § 103.150
Notwithstanding any other law to the contrary and with the exception of a retiree of the participating member agency or a former employee of the participating member agency who is entitled to retirement benefits from the participating member agency, when a person is no longer an employee of a participating member agency covered by the plan, that person and his dependents shall thereupon cease to be covered by the plan.
(L. 1992 H.B. 1574 § 4 subsec. 7)