Tenn. Code Ann. § 37-4-205

The officers and agencies of this state and its subdivisions having authority to place children are empowered to enter into agreements with appropriate officers or agencies of or in other party states pursuant to paragraph (b) of Article V of the Interstate Compact on the Placement of Children. Any such agreement which contains a financial commitment or imposes a financial obligation on this state or subdivision or agency thereof shall not be binding unless it has the approval in writing of the commissioner of children's services in the case of the state and of the chief local fiscal officer in the case of a subdivision of the state.