Tenn. Code § 8-3513
Any member having ten (10) or more years of creditable service who is separated from state service may, in lieu of receiving the payment under § 8-3425, leave such payment in the employees' fund until his minimum service retirement age, at which time he shall be entitled to a retirement allowance calculated in the same manner as provided in § 8-3502, or in lieu thereof he may apply to the board within ninety (90) days after such severance to retire and receive a retirement allowance commencing immediately having a value equal to the present value of such deferred retirement allowance on the basis of the actuarial tables provided for in §§ 8-3427 and 8-3428 and regular interest, except that in the case of class A members who have not attained age fifty-five (55), such allowance shall not commence prior to the attainment of age fifty-five (55).
Anything in this chapter to the contrary notwithstanding, in the case of a class A member who is removed or otherwise involuntarily separated from the state service after ten (10) or more years of creditable service, the minimum amount of benefit payable, including the amount of any disability or old-age insurance benefit under Title II of the Social Security Act to which he is entitled or would be entitled if he made application therefor, shall be the amount of the service retirement benefit which would have accrued to him as a class B member on September 30, 1957.
Until the first payment on account of any benefit becomes normally due, any member may elect to receive the actuarial equivalent of the retirement allowance otherwise payable to him in the form of a reduced allowance, with the provisions that:
Option 1. Upon his death his reduced allowance shall be continued throughout the life of and paid to such person as he shall have nominated by written designation duly acknowledged and filed with the board at the time of his retirement; or
Option 2. Upon his death, one-half (1/2) of his reduced retirement allowance shall be continued throughout the life of, and paid to, such person as he shall have nominated by written designation duly acknowledged and filed with the board at the time of his retirement.
The election of an option shall become effective on the first date the member becomes eligible for service retirement or thirty (30) days after his date of retirement, if earlier, except that no such election shall become effective until thirty (30) days after written application therefor has been filed with the board. Should a beneficiary die before any such election has become effective, he shall be considered as an active member on the date of his death. Should a member die after any such election has become effective, he shall be considered as having been retired on the date of his death. The election of the option may not be changed or revoked by the member after it has become effective, but if the person designated under the option dies prior to the date of retirement of the member, the option shall thereby be revoked.
Notwithstanding anything to the contrary in this section, if a member eligible for service retirement shall file an irrevocable application for retirement setting a date for retirement not less than thirty (30) days and not more than ninety (90) days thereafter, retirement shall become effective as of the date so set and any optional benefit selected shall become effective as of such date.
Until the first payment on account of any retirement allowance becomes normally due, any class A member may elect to convert the allowance otherwise payable on his account after retirement into a retirement allowance of equivalent actuarial value of such amount that, with his benefit under Title II of the Federal Social Security Act, he will receive, so far as possible, approximately the same amount per year before and after the commencement of such benefit.
Until such time as this section becomes effective as provided in § 8-3452, § 8-3513 of the Tennessee Code as enacted by chapter 6 of the Public Acts of 1955, prior to amendment, shall remain in full force and effect.
Should a member retire who was employed subsequent to March 11, 1959 as a commissioned member of the department of safety whose period of creditable service includes service while otherwise employed, anything to the contrary under this chapter notwithstanding, his retirement allowance shall be such proportion of the retirement allowance he would have received had all of his creditable service been as a commissioned member of the department of safety as his years of such service bear to his total period of creditable service plus the proportion of the retirement allowances he would have received had all of his creditable service been as an employee other than a commissioned member of the department of safety as his years of such service bear to his total period of creditable service; provided, however, in no case shall his total retirement allowance be less than the retirement allowance he would have received had all of his creditable service been as an employee other than a commissioned member of the department of safety.
T.C.A. § 8-3513