Tennessee Code Title 8. Public Officers and Employees § 8-34-712

(a) Anything to the contrary notwithstanding, any county official and any county commissioner elected by popular vote, serving in a county having a county commission form of government, taking office on or before July 1, 1974, shall become a member and have the privilege of claiming any prior service such member was entitled to claim under the applicable provision of the superseded Tennessee county officials' retirement system, by completing a form prescribed by the board of trustees, and paying a lump sum in an amount equal to the amount the official would have paid had such official been a member of the Tennessee county officials' retirement system, plus interest at the rate designated in § 8-37-214.

(b) Any county official, as defined in § 8-34-101, may transfer that part of the official's membership so defined and contributions from the Tennessee consolidated retirement system, by completing the necessary forms as prescribed by the board of trustees, and paying in a lump sum the difference between what the official would have contributed had the official been a member of the Tennessee county officials' retirement system and the amount so transferred.