Tennessee Code Title 56. Insurance § 56-7-3714

(a) Upon receipt of information documenting a prior authorization from the enrollee or from the enrollee's healthcare provider, a prior authorization granted to an enrollee from a previous utilization review organization or health carrier must be honored for at least the initial ninety (90) days of an enrollee's coverage under a new health benefit plan.

(b) During the time period described under subsection (a), a health carrier or utilization review organization may perform its own review to approve or deny the prior authorization approved by the enrollee's previous health benefit plan effective when the initial ninety-day period expires.

(c) If there is a change in coverage of, or approval criteria for, a previously authorized healthcare service, then the change in coverage or approval criteria must not affect an enrollee who received prior authorization before the effective date of the change for the remainder of the enrollee's health benefit plan year.

(d) A health carrier or utilization review organization shall continue to honor a prior authorization it has granted to an enrollee when the enrollee changes plans carried or administered by the same health carrier.