For purposes of this Section, a member will be considered to have withdrawn from service if a change in, or transfer of, his position results in his becoming ineligible for continued membership in this System and eligible for membership in another public retirement system under this Act.
The repayment of refunds issued prior to January 1, 1984 shall consist of the amount refunded plus 5% interest per annum compounded annually for the period from the date of the refund to the end of the month in which repayment is made. The repayment of refunds issued after January 1, 1984 shall consist of the amount refunded plus regular interest for the period from the date of refund to the end of the month in which repayment is made. The repayment of the refund of a person who accepts an alternative retirement cancellation payment under Section 14-108.5 shall consist of the entire amount paid to the person under subsection (c) of Section 14-108.5 plus regular interest for the period from the date of the refund to the end of the month in which repayment is made. However, in the case of a refund that is repaid in a lump sum between January 1, 1991 and July 1, 1991, repayment shall consist of the amount refunded plus interest at the rate of 2.5% per annum compounded annually from the date of the refund to the end of the month in which repayment is made.
Upon repayment, the member shall receive credit for the service for which the refund has been repaid, and the corresponding member contributions and regular interest that was forfeited by acceptance of the refund, as well as regular interest for the period of non-membership. Such repayment shall be made in full before retirement either in a lump sum or in installment payments in accordance with such rules as may be adopted by the board.
40 ILCS 5/14-130