Tenn. Code § 49-1517
Any teacher who was a member of the armed forces of the United States, including any person absent from the place of his residence and serving in the armed forces of the United States, or in the merchant marine of the United States, or in the American Red Cross, the United Service Organization, or any other organization attached to and serving with the armed forces of the United States during the period of any war in which the United States has been or may be engaged, or any teacher who has served at the call of the president during the period of any peace time emergency any mobilization of a military reserve unit (or individual member of such unit) including, but not limited to, the United States coast guard or the national guard shall be entitled to service credit for the period of such military service provided he returns to or begins the service of teaching within the meaning of this chapter within a period of two (2) years after he has received his honorable discharge, except that such two (2) year period may be extended to not more than seven (7) years if the board of trustees shall find that the member was regularly attending college in preparation for entering or returning to the teaching profession during the entire period of time in excess of two (2) years following his honorable discharge. Any teacher with credit for such military service who continues as a member until retirement shall at the time of retirement be entitled to have his accumulated contributions increased by the contributions he would have made for the period of such military service on the basis of the salary received by him during his first year of teaching service after such period, together with regular interest thereon to the date of his retirement, and such service shall be included in his creditable service for the purpose of determining his state annuity.
Any other provision of law to the contrary notwithstanding any person called into military service by the president, in time of war or national emergency, or any mobilization of a military reserve unit (or individual member of such unit) including, but not limited to, the United States coast guard or the national guard within ninety (90) days after leaving service as a teacher, as defined in this chapter, shall be entitled to retirement credit for the period of his military service upon condition he returned to teaching service, as defined in this chapter, within seven (7) years from the date of his honorable discharge.
The provisions of this section shall not apply to any period of military service arising from voluntary enlistment or reenlistment during any peace time period.
T.C.A. § 49-1517