Illinois law makes it very clear that a prenup can cover maintenance (alimony), but cannot cover child custody. Illinois courts always have the power to determine which parent should be the custodial parent of a child, regardless of any prior agreements between the parties.

However, the law is a little murkier surrounding Child Support. A child’s right to support may not be adversely affected by the terms of a prenup. My interpretation is that a prenup could provide for a generous amount of Child Support, but the best practice is to leave all child-related matters out of your prenup.

Illinois law at 750 ILCS 10/4 defines what a can be contained in a prenup. The parties may make an agreement with respect to the following:

• the rights and obligations of each of the parties in any of the property of either or both of them whenever and wherever acquired or located;
• the right to buy, sell, use, transfer, exchange, abandon, lease, consume, expend, assign, create a security interest in, mortgage, encumber, dispose of, or otherwise manage and control property;
•  the disposition of property upon separation, marital dissolution, death, or the occurrence or nonoccurrence of any other event;
•  the modification or elimination of spousal support;
•  the making of a will, trust, or other arrangement to carry out the provisions of the agreement;
•  the ownership rights in and disposition of the death benefit from a life insurance policy;
•  the choice of law governing the construction of the agreement;
•  any other matter, including their personal rights and obligations, not in violation of public policy or a statute imposing a criminal penalty;
• the right of a child to support may not be adversely affected by a premarital agreement.