(a) Any member who has previously served on active military duty is entitled to receive additional years of service for the purpose of determining his or her years of credited service for a period equal to the active military duty not to exceed five years, subject to the following:

(1) That he or she has been honorably discharged from the Armed Forces;

(2) That he or she substantiates by appropriate documentation or evidence his or her period of active military duty; and

(3) That he or she is receiving no benefits from any other retirement system for his or her active military duty.

(b) In addition, any member who while in covered employment was commissioned, enlisted or inducted into the Armed Forces of the United States or, being a member of the reserve officers' corps, was called to active duty in the Armed Forces between September 1, 1940, and the close of hostilities in World War II, or between the June 27, 1950, and the close of the armed conflict in Korea on July 27, 1953, between August 1, 1964, and the close of the armed conflict in Vietnam, or during any other period of armed conflict by the United States whether sanctioned by a declaration of war by congress or by executive or other order of the president, is entitled to and shall receive credited service, for a period equal to the full time that he or she has or, pursuant to that commission, enlistment, induction or call, shall have served with the Armed Forces subject to the following:

(1) That he or she has been honorably discharged from the Armed Forces;

(2) That within ninety days after honorable discharge from the Armed Forces, he or she presented himself or herself to the county commission and offered to resume service as a deputy sheriff; and

(3) That he or she has made no voluntary act, whether by reenlistment, waiver of discharge, acceptance of commission or otherwise, to extend or participate in extension of the period of service with the Armed Forces beyond the period of service for which he or she was originally commissioned, enlisted, inducted or called.

(c) The total amount of service allowable under subsections (a) and (b) of this section may not exceed five years.

(d) Any service credit allowed under this section may be credited one time only for each deputy sheriff, regardless of any changes in job title or responsibilities.

(e) Notwithstanding the preceding provisions of this section, contributions, benefits and service credit with respect to qualified military service shall be provided in accordance with Section 414(u) of the Internal Revenue Code. For purposes of this section, "qualified military service" has the same meaning as in Section 414(u) of the Internal Revenue Code. The retirement board is authorized to determine all questions and make all decisions relating to this section and, pursuant to the authority granted to the retirement board in section one, article ten-d, chapter five of this code, may promulgate rules relating to contributions, benefits and service credit to comply with Section 414(u) of the Internal Revenue Code.