Section 2-1.5. Advancements and their adjustment

(a)  An advancement is an irrevocable gift intended by the donor as an
  anticipatory distribution in complete or  partial  satisfaction  of  the
  interest  of  the  donee in the donor's estate, either as distributee in
  intestacy or as beneficiary under an existing will of the donor.
    (b) No advancement shall affect the distribution of the estate of  the
  donor unless proved by a writing contemporaneous therewith signed by the
  donor   evidencing  his  intention  that  the  gift  be  treated  as  an
  advancement, or by the donee acknowledging that such was the intention.
    (c) When so proved, the advancement is part of the estate of the donor
  for the purpose of distribution. If such  advancement  is  equal  to  or
  greater  than  the  interest of the donee, whether in intestacy or under
  the will, such donee or his successor in interest may not share  in  the
  distribution  of  the  estate;  but if less than such intestate share or
  testamentary interest, the donee or his successor in interest  may  take
  his  intestate  share  or testamentary interest reduced by the amount of
  the advancement.
    (d) Unless otherwise provided in a writing  contemporaneous  with  the
  advancement and signed by the donor:
    (1)  An advancement, made as provided in this section, may be adjusted
  out of the property of the donor in such manner as may be equitable.
    (2) The advancement shall have the value at which it is appraised  for
  estate  tax purposes, or, if not included in the gross taxable estate of
  the donor, the value at which it would have been appraised  if  included
  therein.
    (e)  Nothing  in  this section shall increase or decrease the elective
  share of a surviving spouse under either 5-1.1 or 5-1.1-A except to  the
  extent authorized by paragraph (b) of those sections.