Tennessee Code Title 8. Public Officers and Employees § 8-34-607

(b) To purchase service under this section, a member shall make a lump sum payment equal to the actuarial cost as determined by the retirement system without creating unfunded accrued liability at the date the service is established. Service established under this section must be under the terms of the retirement system plan as they exist at the time the service is established. Upon the member making the required payment and providing any forms or other documentation required by the retirement system, the member must be credited with the years of service from the other plan.

(c) This section does not permit the establishment of service that would have been considered prior service pursuant to § 8-35-203 or service rendered to a withdrawn employer pursuant to § 8-35-218.

(d) Salaries earned for service established pursuant to this section must not be used in determining a member's average final compensation.

(e) This section applies on such date as the retirement system's operating systems are able to accommodate the payment for service as provided in this section. The state treasurer shall make such determination.

(f) For purposes of this section, the term “political subdivision” includes, but is not limited to, a city, metropolitan government, county, utility district or agency or instrumentality of the political subdivision, in this state.