Tennessee Code Title 67. Taxes and Licenses § 67-8-310

(a) The value of every future, contingent or limited estate, income, interest or annuity for any life or lives in being shall, so far as possible, be determined by the rule, method and standard of mortality and of value set forth in the actuarial tables of mortality in use by the internal revenue service for federal estate tax purposes at the time of the decedent's death. The value of the interest remaining after any such temporary interest shall be determined by deducting the computed value of the temporary estate from the value of the entire property in which such interest exists. Unless otherwise provided by the transferor, the tax on such temporary interests and remainders shall be payable out of the property in which such temporary interests and remainders exist.

(b) In the event the internal revenue service issues regulations at any time that provide for an election between tables, such election shall be available at the same time and in the same manner to the personal representative of the estate with respect to the state inheritance tax return, and shall be allowed by the commissioner upon the filing of a duplicate copy of the election filed with the internal revenue service.