Ala. Code § 45-37A-51.140

The Legislature reserves the power to amend, alter, or repeal this subpart or any provision thereof. If any person who may be entitled to voluntarily retire and obtain a retirement allowance under this subpart shall so voluntarily retire before exercise of the reserved power such person shall have a contractual lien upon the fund for each and every amount to which he or she may be or become entitled in accordance with the terms of the law existing at the time of such voluntary retirement. If any employee becomes totally disabled before exercise of the reserved power, such employee shall have a contractual lien upon the fund for each and every amount to which he or she may be or become entitled in accordance with the terms of the law existing at the time of commencement of such disability.