Upon the termination of a contract, all memberships in this system existing because of that contract continue in existence to the extent that there are accumulated contributions to the credit of each local member, but any member may elect to withdraw his or her accumulated contributions if the member is not employed in a position subject to coverage by the system at the time of election. The status of any member who does not withdraw his or her accumulated contributions shall be the same as if the public agency had continued as a contracting agency. The membership of any member who is eligible and who elects to withdraw his or her accumulated contributions shall be terminated forthwith, and he or she shall not be entitled to any further benefit based upon service credited as an employee of the contracting agency, nor shall he or she have the right to redeposit those withdrawn contributions upon again becoming a member of this system. The portion of the contributions of the contracting agency held under Section 20576 to the credit of each member shall be determined by the board, and may be adjusted from time to time prior to termination of membership. A member whose membership continues under this section is subject to the same age and incapacity requirements as apply to other members for service or for disability retirement, but he or she is not subject to a minimum service requirement. Except as provided in Section 20578, he or she shall receive the retirement benefits as his or her accumulated contributions, together with the portion of the excess of the contributions of the contracting agency as are credited to him or her, shall provide, as determined by the board, but the provisions of this part relative to minimum retirement allowances shall not apply to him or her, nor shall those benefits exceed the benefits provided by the contract prior to its termination. Upon the death of a member, the basic death benefit shall be his or her accumulated contributions.