Mo. Rev. Stat. § 41.310

41.310. Officers — retirement. — 1. Officers, warrant and flight officers and enlisted persons shall be retired from active service and placed on the retired list upon attaining the retirement age of their grade, as fixed in regulations governing the Armed Forces of the United States, or by reason of physical disability retirement while serving with the Armed Forces of the United States. Any officer, warrant or flight officer or enlisted person who has served for ten years in the organized militia may upon his own application and approval by the governor be placed upon the retired list without cost to the state. Any officers retired after fifteen years of satisfactory service may be considered and retired in one grade higher than the highest grade held during their period of active service without cost to the state. Service in the Armed Forces of the United States in time of war shall be computed as state service for the purpose of this section.

2. The governor may detail, with their own consent, officers of the retired list to active duty and return them to the retired list in his discretion. Officers retired for age shall not be detailed to command troops, but only to perform duties of staff corps or department, or to sit on boards, except in time of war or other emergency, or imminent danger thereof, when retired officers may be detailed by the governor, without their consent, to perform any military duty designated by him.

(RSMo 1939 §§ 15030, 15103, A.L. 1951 p. 654 §§ 49, 50, A.L. 1953 p. 561, A.L. 1961 p. 479) Prior revisions: 1929 §§ 13810, 13903; 1919 § 9146