(a)

(1) Any person who becomes a teacher, a general employee, a state police officer, a wildlife officer, a firefighter or a police officer on or after July 1, 1972, shall become a member of the retirement system as a condition of employment.
(2) Notwithstanding this section or any other law to the contrary, no state department, commission, institution, board, agency, instrumentality or entity of or affiliated with state government shall be authorized to cover its otherwise eligible employees in the retirement system unless the general assembly approves the annual operating budget for the entity, or unless the entity has specific Tennessee state statutory authority to cover its otherwise eligible employees in the retirement system and the entity obtains written advice from nationally recognized counsel employed by the retirement system in the area of government employee benefit plans that the entity is eligible to participate in a governmental plan as defined by Internal Revenue Code § 414(d) ( 26 U.S.C. § 414(d) ), as amended. The foregoing also applies to any person seeking admission to the retirement system whose compensation is paid, in whole or in part, from funds not appropriated by the general assembly. Notwithstanding this section or any other law to the contrary, the funds necessary to fund any prior service of such persons must be appropriated by the general assembly or paid by another governmental entity.
(b) Any person who on June 30, 1972, is a member of a superseded system shall become a member of the retirement system as of July 1, 1972.
(c) Any person who on June 30, 1972, is not a member of a superseded system and who is employed as a general employee, a state police officer, a wildlife officer, a state judge, a county judge, an attorney general, a commissioner, a person in the employ of a political subdivision of the state participating in the retirement system pursuant to part 2 of this chapter or a teacher other than a teacher eligible for membership in a local retirement system, may elect to become a member of the retirement system as of July 1, 1972; provided, that within ninety (90) days following July 1, 1972, such person files with the board of trustees on a form prescribed by the board a notice of such person’s election to become a member. Any employee may elect to become a member; provided, that such person files with the board of trustees a notice of election to become a member.