Tenn. Code § 49-1527
The accumulation account shall be the account in which shall be accumulated the reserves for the payment of that part of all retirement allowances and other benefits not provided by the members' accumulated contributions, to which upon retirement a members' accumulated contributions shall be transferred and from which shall be paid all retirement allowances and other benefits. Contributions to the accumulation account shall be made as set forth in sections 49-1528 - 49-1531. Should a beneficiary retired on account of disability or service retirement be restored to active service prior to age sixty (60) with a compensation not less than his average final compensation at the time of his last retirement his teacher annuity reserve shall be transferred from the accumulation account to the members' contributions account and credited to his individual account therein.
T.C.A. § 49-1527