A member is entitled to eligibility service during a leave of absence if the leave of absence: is approved by the Board of Trustees under regulations that apply to all members similarly situated; and is not otherwise recognized as eligibility service under this subtitle. To receive service credit for a leave of absence described under subsection (a) of this section, a member shall pay the member contributions with regular interest, if any, as determined by the Board of Trustees under regulations that apply to all members similarly situated.