Mo. Rev. Stat. § 590.117
The department shall provide by administrative rule for the requirements for continuing certification of an inactive or unemployed peace officer during the term of such inactivity or unemployment, provided that the certification of such peace officers shall expire after five consecutive years of such inactivity or unemployment. The cost of any continuing law enforcement education and training required to maintain such certification shall be paid by the inactive or unemployed peace officer.
(L. 1994 S.B. 475)