Tennessee Code Title 8. Public Officers and Employees § 8-35-103

(a) Any person who becomes a part-time state employee or part-time teacher on or after July 1, 2025, shall become a member of the retirement system unless the person elects not to participate in the retirement system by submitting a written, irrevocable election to the Tennessee consolidated retirement system no later than thirty (30) calendar days after the person's first day of employment.  Any person who becomes a part-time employee on or after July 1, 2025, for an employer participating under part 2 of this chapter that allows part-time employee participation in the retirement system, shall become a member of the retirement system unless the person elects not to participate in the retirement system by submitting a written, irrevocable election to the Tennessee consolidated retirement system no later than thirty (30) calendar days after the person's first day of employment.

(b) A person who became a part-time employee between July 1, 1984, and June 30, 2025, and made an irrevocable election to participate in the retirement system shall continue participation in the retirement system, as provided in chapters 34-37 of this title.

(c) The following employees are not eligible for membership in the retirement system:

(d) Part-time employees working in institutions of higher education are eligible for membership in the optional retirement plan found in chapter 25, part 2 of this title if the institution certifies that the employee is a teacher.

(e) In cases of doubt as to the classification of an employee, the board of trustees shall determine from objective criteria whether an employee is properly classified.

(f) Any retiree who accepts part-time employment with an employer participating in the retirement system will be considered as restored to employment within the meaning of chapter 36, part 8 of this title, regardless of whether the retiree is eligible for membership.