Tenn. Code § 8-3604
The actuary of the retirement system shall compute the rates of contribution payable by employers in behalf of their employees who become members under the provisions of this chapter by an actuarial evaluation similar to that established by §§ 8-3427 and 8-3428. Each political subdivision employing members participating in the system as provided in this chapter, shall make a special accrued liability contribution on account of the participation of its employees in the retirement system, which shall be determined by an actuarial valuation of the employer's share of the accrued liability on account of the employees of such political subdivision who elected to become members. This special accrued liability contribution shall be subject to such adjustments as may be necessary on account of any additional prior service credits awarded to employees of such political subdivision or changes in provisions relating to such employees. The expense of making such initial valuation shall be assessed against and paid by the political subdivision on whose account it is necessary. The contributions so computed together with a pro rata share of the cost of the administration of the retirement system, based upon the payroll of the employees, shall be certified by the board to the chief fiscal officer of the political subdivision. The amounts so certified shall be a charge against the political subdivision. The chief fiscal officer of each such political subdivision shall pay to the state treasurer the amount certified by the board as payable under the provisions of this section, and the state treasurer shall credit such amounts, when paid, to the appropriate funds of the retirement system.
T.C.A. § 8-3604