Tenn. Code Ann. § 62-6-516: Exemptions

(a) This part does not apply to the official transactions of an authorized representative of the United States or an instrumentality of the United States, any state or territory of the United States, any municipality or county of a state or territory or any instrumentality of a state or a political subdivision of an instrumentality of a state.

(b) If home improvement contractors in a county are exempted from licensure under this chapter on July 1, 2007, due to a county exclusion, the legislative body of the county may, by a two-thirds (2/3) majority vote, elect to make this part applicable in the county. Any county electing to come within this part shall so notify the board.