Tennessee Code Title 8. Public Officers and Employees § 8-35-207

(a) Any political subdivision which elects to authorize all its employees to become members of the retirement system after June 30, 1978, shall have the option to exclude from their retirement benefit plan cost-of-living benefits as provided by § 8-36-701 on account of retired employees of the employer.

(b) It is further provided that the chief legislative body of any political subdivision employer may elect at a later date to provide cost-of-living benefits in accordance with § 8-36-701 by legally adopting a resolution for an actuarial study and thereafter by legally adopting a resolution approved by a two-thirds ( 2/3 ) majority of the governing body to accept the associated liability and costs to provide such benefits. This increase in benefits will become effective the following July 1 after the adoption of the resolution. No retroactive benefits are to be paid under this subsection (b).