Can a Prenup Exempt Me From Paying Child Support?

 Posted on October 13, 2026 in Child Support

Child support is one of the few issues that can never be decided in advance by a prenuptial agreement. Child support in Illinois belongs to the child, not to either parent. It’s intended to give the child the resources they would have had if their parents had stayed together, which is why a prenuptial agreement can’t waive it, lower it, or exempt one parent from paying it.

If you signed a prenup and are facing a divorce in 2026, our Glendale Heights, IL child support lawyers can help you understand how your prenup could affect your divorce decree.

Can a Prenup Affect Child Support in Illinois?

Illinois law doesn’t allow a premarital agreement to reduce a child’s support. Under 750 ILCS 10/4(b), "The right of a child to support may not be adversely affected by a premarital agreement." A clause that says one parent doesn’t have to pay support, or caps support at a set amount, won’t be enforced. Neither parent can trade it away in exchange for property or other terms.

The same principle applies to agreements made during the divorce. Under 750 ILCS 5/502(b), a judge isn’t bound by the terms of a divorce settlement that deal with child support or parental responsibilities. Even if both parents sign off on a support amount, the court will still review it.

Is Spousal Support Treated Like Child Support in a Prenuptial Agreement?

A court may enforce spousal support provisions. Child support and spousal maintenance are separate, and spousal support is not limited by the same laws as child support. A prenup may legally limit or waive maintenance under 750 ILCS 10/4.

However, a court can still require support if enforcing the agreement would cause undue hardship because of circumstances that could not reasonably have been predicted when the prenup was signed.

How Is Child Support Calculated in Illinois?

Illinois uses an income shares model that adds both parents’ net incomes to determine how much total support is owed. It then splits that amount based on each parent’s share of the total income. Parenting time and costs like health insurance and child care can also affect the final number.

Judges have more discretion when dealing with higher-income couples (those whose combined net income is above $27,374.99 a month under the 2026 Illinois support schedule) and may order additional support for things like school tuition or extracurricular expenses.

For child support purposes, gross income includes income from all sources, with a few exceptions such as certain public benefits.

Can Parents Make Their Own Agreement About Child Support in Illinois?

The state guidelines are presumed to be correct when it comes to the amount of child support. A judge may set a different amount in some cases if the guideline figure would be unjust or inappropriate. The judge has to put the reasons for the change in writing. Examples may include a child’s special medical needs or unusual expenses.

Parents can propose an amount that’s different from the guidelines, but they can’t simply decide on an amount between themselves. The judge will look at whether the proposed amount serves the child’s best interests before approving it.

Child support can also be changed later if there’s a substantial change in circumstances, such as a major drop in income, and a prenup can’t prevent either parent from asking for a modification to child support orders.

What Happens if an Illinois Prenup has a Child Support Clause?

If a prenuptial agreement includes provisions that waive or reduce a child's right to child support, the court will not honor them. A provision that provides additional support is not automatically invalid, but the court must still determine what is appropriate for the child.

The rest of the prenup may still be valid, though. A court can set aside the invalid child support clause and enforce the property and financial terms, depending on how the agreement was written.

Call a Plainfield, IL Child Support Lawyer Today

A prenup may protect your property, but it won’t settle what you’ll pay or receive in child support. Our Glendale Heights, IL family law attorneys can review your agreement and your income to help you understand what support may look like for your family.

At The Law Offices of Robert F. Kramer, Ltd., we bring over 40 years of combined experience, including accomplished trial and appellate work. We’ll guide you through each step of your divorce settlement, including navigating child support.

Call The Law Offices of Robert F. Kramer, Ltd. at 630-785-2400 to schedule your free 30-minute initial consultation today.