Child Support
750 ILCS 5/505 — both parents' net incomes added together, then shared by percentage
The court may order either or both parents to pay an amount reasonable and necessary for a child's support, including the child's physical, mental and emotional health needs. A child here means any child under 18, and a child over 18 who has not reached 19 and is still attending high school.
Who handles this in Illinois: legal aid programs, lawyer referral and the state offices, listed in the Illinois directory.
| Step | What the court does |
|---|---|
| StepFirst | What the court doesDetermines each parent's monthly net income |
| StepSecond | What the court doesAdds them together into the parents' combined monthly net income |
| StepThird | What the court doesTakes the amount from the state's schedule for that combined income and the number of children |
| StepFourth | What the court doesWorks out each parent's percentage share of that amount |
The receiving parent's share is not paid to the other parent and is presumed to be spent directly on the child. The court applies the guidelines unless it finds that applying them would be inappropriate, after considering the child's best interests and factors such as the child's and parents' financial resources and needs, the standard of living the child would have had, and the child's physical, emotional and educational needs.
When each parent has 146 or more overnights. If each parent exercises 146 or more overnights a year with the child, the basic obligation is multiplied by 1.5 to calculate the shared care obligation. Each parent's portion is multiplied by the percentage of time the child spends with the other parent, the two amounts are offset, and the parent owing more pays the difference.
An order has to name the date the current support ends, and it cannot be earlier than the child turning 18. For a child who will graduate from high school after turning 18, it cannot be earlier than graduation or the child turning 19, whichever comes first. An order can be modified on a showing of a substantial change in circumstances.
The schedule and worksheets are in the Department of Healthcare and Family Services' rules rather than in the statute, and the section also covers health insurance, child care and the income a parent could be earning. How they apply to a particular household are questions for a licensed Illinois attorney.
Sources for this section (2)
- 750 ILCS 5/505 — Child support
- 750 ILCS 5/510 — Modification and termination of provisions for maintenance, support, educational expenses, and property disposition
Legal information, not legal advice. Verified as of October 2026. Applying it to a particular situation is the work of a licensed Illinois attorney.