Miss. Code § 21-29-139
If any member of said fire and/or police department who has been in paid fire and/or police department service for as long as twenty (20) years before making application hereinafter mentioned, the last ten (10) years of which shall have been continuous in the city in which the application is made, shall make written application for retirement and relief, the board of disability and relief shall, without medical examination of disability, retire him from active service in said fire and/or police department. Upon such retirement from active service, said board of disability and relief shall order the payment to such retired member monthly from said fund a sum equal to fifty percent (50%) of the average monthly base salary and longevity pay received as salary by such member in the six-month period next before the filing of such application in said fire and/or police department. Such payments shall thereafter be made to said retired member for life, such payment to be known as "retired relief."
Any member of the fire and/or police department who has been in paid fire and/or police department service for longer than twenty (20) years in a municipality shall be entitled and shall receive additional retired relief payment for life in a sum equal to one and seven-tenths percent (1-7/10%) of the same average monthly base salary and longevity pay received by such member in the six-month period next preceding the filing of said application, for each full year of service in excess of twenty (20) years' service. However, no retired relief payment to any member shall exceed sixty-six and two-thirds percent (66-2/3%) of the average monthly base salary and longevity pay received by a member for the six-month period next preceding the filing of said application.
The said board shall, when a member of the fire and/or police department reaches the age of sixty-five (65), retire him from active service in said fire and/or police department and order the payment of such funds as the member is entitled to hereunder.
Periods of time in which a member may have been inactive on account of physical or mental disability shall not be excluded in computing the twenty-year period and the ten-year period hereinbefore mentioned. Periods of time within which a member may have been absent from his employment while in active service of the Army or Navy of the United States, United States Marine Corps or the United States Coast Guard between September 16, 1940, and July 25, 1947, or while as a civil employee engaged by the Army and Navy while serving outside the continental United States shall not be excluded in computing the twenty-year period and the ten-year period hereinbefore mentioned, provided that the discharge or release of such member from the armed forces was under conditions other than dishonorable. Any member who has been retired or is voluntarily retired hereunder, or who has received relief or disability benefits hereunder, shall be required to perform such duties as then may be required of him.
Provided, however, in any city having a population of nineteen thousand (19,000) but less than twenty thousand (20,000), according to the 1970 census, the periods of time not exceeding four (4) years within which a member of the fire or police departments may have been absent from his employment while in active service in the Armed Forces of the United States, shall not be excluded in computing the twenty-year period and the ten-year period mentioned in this section.
Miss. Code § 21-29-139