Tennessee Code Title 67. Taxes and Licenses § 67-8-317

(a) If the gross estate includes property upon the transfer of which to the decedent a tax was previously and within five (5) years imposed by this state, or property that has been received by the decedent in exchange for property upon which a tax was so imposed, a credit on account of such tax actually so previously paid shall be allowed against the tax imposed with respect to the particular property, but not to exceed the amount of tax imposed with respect to the property on the present transfer.

(b) The credit for previously paid tax computation shall be the lesser of the following:

(c) The five-year period shall be computed from the date of death of the prior decedent and not from the date of payment of such tax.