Tenn. Code § 33-6-309
If at any time within the seventy-two hour period it is determined that the person continues to require immediate observation, assessment, and treatment in accordance with this part and that the requirement is likely to continue beyond the seventy-two hour period, the person shall be moved immediately to an appropriate hospital or treatment resource authorized to receive and detain persons with mental illness or serious emotional disturbance under chapter 6, part 4 of this title. The person shall be evaluated for admission and, if appropriate, shall be admitted in accordance with chapter 6, part 4 of this title, and if the person is so admitted, the fifteen-day retention period of chapter 6, part 4 of this title, shall be reduced by the number of days the person was detained under this part. Any person moved to a hospital pursuant to this section shall be moved without regard to the transfer provisions of this title. Evaluation for admission to a state-owned or operated hospital or treatment resource must conform to § 33-6-105.
T.C.A. § 33-6-309