(40 ILCS 5/8-230.6)
Payments and rollovers.
(a) The Board may adopt rules prescribing the manner of repaying refunds
and purchasing any other credits permitted under this Article. The rules may
prescribe the manner of calculating interest when payments or repayments
are made in installments.
(b) Rollover contributions from other retirement plans qualified under the
Internal Revenue Code of 1986 may be used to purchase any optional credit or
repay any refund permitted under this Article.
(Source: P.A. 90-31, eff. 6-27-97.)