Do I Have To Pay Child Support With Joint Custody in Illinois?

 Posted on July 14, 2025 in Child Support

A common misconception is that parents who share equal custody, known as parental responsibilities in Illinois, do not have to pay child support. However, under Illinois law, that is not necessarily true. Even when parents split parenting time 50/50, one parent might still be required to pay support if there is a significant disparity in income. A Wheaton, IL child support attorney can help you figure out how the law applies to your specific situation.

How Is Child Support Calculated Under Illinois Law?

Illinois uses an "income shares" model to calculate child support. This method, explained in Section 505 of the Illinois Marriage and Dissolution of Marriage Act, looks at the combined net income of both parents to determine how much money should go toward raising the child. The idea is that a child should receive the same financial support they would have if their parents stayed together.

Once the parents’ total income is determined, each parent’s share of the financial obligations to the child is figured out based on their income percentage. For example, if one parent earns 65 percent of the combined income, they are responsible for 65 percent of the total child support amount.

What Will a Parent With 50/50 Custody Pay in Child Support in Illinois?

The allocation of parental responsibilities dictates how child support is determined. Illinois law takes parenting time into account, but income differences still play a major role. If both parents have similar incomes and truly split time equally, neither parent may owe support. However, if one parent earns significantly more, they might still have to pay.

The law also includes a special rule for shared parenting. Under Section 505(a)(3.8), if both parents have at least 146 overnights per year with the child, the basic child support obligation is multiplied by 1.5 to account for the higher costs of maintaining two households. Then, the amount each parent owes is offset to determine whether a payment is needed.

For example, assume your co-parent earns $90,000 a year, and you earn $40,000. Even with a 50/50 custody split, your co-parent could still be ordered to pay some support so that the child’s lifestyle stays more balanced between households.

What Factors Are Considered When Determining Child Support Payments in Illinois?

Income and parenting time are not the only elements Illinois courts consider when deciding child support. The law, found in 750 ILCS 5/505(a)(3.7), allows other factors to affect how much support one parent might pay. For example, the court may look at the following:

• Other support obligations: If a parent already has other children to support from a different relationship, that can lower their child support obligation.

• Healthcare and childcare costs: Parents often share costs for health insurance, medical expenses, and daycare, proportionate to their incomes.

• Extraordinary expenses: Special needs, school costs, or extracurricular activities can also influence child support amounts.

Illinois courts have the power to adjust the calculated support amount if following the standard guidelines would be unfair. Section 505 allows judges to deviate from the guidelines at their discretion, based on a child’s needs or the parents’ financial situations.

Talk to a Wheaton, IL Child Support Attorney Today

Child support orders can be complex, especially when parents share parental responsibilities. To get clear answers and protect your financial future, talk to a Wheaton, IL child support lawyer at Davi Law Group today. We can help you understand what would be considered a fair support amount for your child. Call 630-657-5052 to schedule a free consultation.