The Illinois Marriage and Dissolution of Marriage act, at 750 ILCS 5/503, defines marital property as follows.
(a) For purposes of this Act, “marital property” means all property, including debts and other obligations, acquired by either spouse subsequent to the marriage, except the following, which is known as “non-marital property”:
(1) property acquired by gift, legacy or descent or property acquired in exchange for such property;
(2) property acquired in exchange for property acquired before the marriage;
(3) property acquired by a spouse after a judgment of legal separation;
(4) property excluded by valid agreement of the parties, including a premarital agreement or a postnuptial agreement;
(5) any judgment or property obtained by judgment awarded to a spouse from the other spouse except, however, when a spouse is required to sue the other spouse in order to obtain insurance coverage or otherwise recover from a third party and the recovery is directly related to amounts advanced by the marital estate, the judgment shall be considered marital property;
(6) property acquired before the marriage, except as it relates to retirement plans that may have both marital and non-marital characteristics;
(6.5) all property acquired by a spouse by the sole use of non-marital property as collateral for a loan that then is used to acquire property during the marriage; to the extent that the marital estate repays any portion of the loan, it shall be considered a contribution from the marital estate to the non-marital estate subject to reimbursement;
(7) the increase in value of non-marital property, irrespective of whether the increase results from a contribution of marital property, non-marital property, the personal effort of a spouse, or otherwise, subject to the right of reimbursement provided in subsection (c) of this Section; and
(8) income from property acquired by a method listed in paragraphs (1) through (7) of this subsection if the income is not attributable to the personal effort of a spouse.
Property acquired prior to a marriage that would otherwise be non-marital property shall not be deemed to be marital property solely because the property was acquired in contemplation of marriage.
The court shall make specific factual findings as to its classification of assets as marital or non-marital property, values, and other factual findings supporting its property award.