760 ILCS 3/1319

To the extent a powerholder releases or fails to exercise a general power of appointment other than a power to revoke, amend, or withdraw property from a trust: (1) the gift-in-default clause controls the disposition of the unappointed property; or (2) if there is no gift-in-default clause or to the extent the clause is ineffective: (A) except as otherwise provided in subparagraph (B), the unappointed property passes to: (i) the powerholder if the powerholder is a permissible appointee and living; or (ii) if the powerholder is an impermissible appointee or not living, the powerholder's estate if the estate is a permissible appointee; or (B) to the extent the powerholder released the power, or if there is no taker under subparagraph (A), the unappointed property passes under a reversionary interest to the donor or the donor's transferee or successor in interest.