Child Support Law in Illinois
This page covers child support law as it applies in Illinois — the state and federal laws that govern it, filing deadlines, where to get help, and notable in-state decisions. For what child support protects generally, see the national overview.
Compiled from primary legal sourcesNot legal adviceHow we source this
Quick answer
In Illinois, child support is calculated using the Income Shares Model, which considers both parents' net incomes to set a fair support amount based on what parents typically spend on their children. Both parents have a legal duty to support their child, whether or not they were ever married. The Illinois Department of Healthcare and Family Services offers free help setting up, collecting, and enforcing support orders. Some deadlines are as short as 60 days, so act quickly if you recently signed a parentage form or received a support order.
Laws that govern child support in Illinois
Illinois state law
- Illinois Marriage and Dissolution of Marriage Act — Child Support Guidelines750 ILCS 5/505
Establishes the Income Shares Model for calculating child support and requires every order to include a termination date.
- Illinois Marriage and Dissolution of Marriage Act — Modification of Support Orders750 ILCS 5/510
Sets the standard for modifying existing child support orders, including the substantial-change-in-circumstances test and the 20-percent inconsistency rule.
- Illinois Marriage and Dissolution of Marriage Act — Educational Expenses750 ILCS 5/513.5
Allows courts to order parents to contribute to a child's post-secondary educational costs, generally capped at the cost of attending an Illinois public university.
- Illinois Parentage Act of 2015750 ILCS 46/
Governs how legal parentage is established in Illinois, including the Voluntary Acknowledgment of Parentage process and court adjudication proceedings.
- Illinois Non-Support Punishment Act750 ILCS 16/
Makes willful failure to pay court-ordered child support a criminal offense and sets out penalties for non-payment.
Federal law
- Personal Responsibility and Work Opportunity Reconciliation Act of 1996
Welfare reform: replaced AFDC with TANF, imposed work requirements and time limits, restricted immigrant benefits.
Illinois-specific deadlines for child support cases
Enter the date your problem happened to see which deadlines may already have passed. Not every deadline applies to every situation — this is a general estimate, not legal advice. Deadlines can be shorter, paused, or extended.
- Deadline to rescind a Voluntary Acknowledgment of Parentage: 60 days
Either parent who signed the Voluntary Acknowledgment of Parentage may rescind it by submitting the proper form to the Department of Healthcare and Family Services within 60 days of the filing date. After 60 days, the acknowledgment carries the same legal weight as a court order.
750 ILCS 46/ (Illinois Parentage Act of 2015), Article 3
- Deadline to challenge a Voluntary Acknowledgment of Parentage in court based on fraud, duress, or material mistake of fact: Generally 2 years
After the 60-day rescission window closes, a Voluntary Acknowledgment of Parentage can be challenged only in court on the grounds of fraud, duress, or material mistake of fact. This type of challenge is generally allowed only within 2 years of the filing date.
750 ILCS 46/ (Illinois Parentage Act of 2015), Article 3
- Automatic review cycle for child support orders administered by the state: Every 3 years
The Illinois Division of Child Support Services reviews child support orders every three years to see whether the amount should be updated. Either parent may also request a review at any time outside this cycle if circumstances have changed significantly.
750 ILCS 5/510
These deadlines are general estimates. They can be shorter than they appear, and can be paused (“tolled”) or extended in specific situations. This is not legal advice. If any deadline is near or has passed, talk to a lawyer right away.
Where to go & how to get help
Government agencies and non-profit legal-help organizations for child support in Illinois.
The state child support enforcement agency that establishes support orders, collects payments, and enforces orders at no cost; call 1-800-447-4278 or apply online.
- Illinois Legal Aid Onlinelegal aid
Provides free self-help legal information, court forms, and referrals to free legal aid organizations for low-income Illinois residents with child support questions.
Connects people with licensed Illinois family-law attorneys; the first half-hour consultation is available at a reduced rate for referral service callers.
Official U.S. government starting point for finding free or low-cost legal help and legal-aid programs near you.
Locate the LSC-funded legal-aid organization that serves your county for civil (non-criminal) legal problems.
Find your state or local bar association lawyer-referral service and free legal-answer programs.
Find your state attorney general to file consumer-protection, civil-rights, or other complaints.
How to take action in Illinois
- 1
Establish legal parentage if the parents were not married
Before a court can order child support, the law must recognize who the parents are. Unmarried parents can sign a Voluntary Acknowledgment of Parentage at the hospital or contact the Illinois Department of Healthcare and Family Services for help with the process.
- 2
Apply for child support services through the Illinois Department of Healthcare and Family Services
The Division of Child Support Services provides free services including locating the other parent, establishing a support order, and collecting payments. Call 1-800-447-4278 or visit hfs.illinois.gov/childsupport to apply.
- 3
Gather financial records before your hearing
Illinois uses the Income Shares Model, so the incomes of both parents are needed to calculate the correct support amount. Bring recent pay stubs, tax returns, and information about the child's health insurance costs.
- 4
Obtain a court or administrative order setting the support amount
A judge or an administrative process through the Department of Healthcare and Family Services will set the monthly support amount and issue an order. All Illinois support orders include automatic wage withholding so payments come directly from the paying parent's paycheck.
- 5
Request a review if your situation changes significantly
Either parent can ask for a review of the support amount at any time if there has been a major change in income, custody, or the child's needs. Cases with Department of Healthcare and Family Services involvement are also reviewed automatically every three years.
- 6
Report non-payment and use enforcement tools
If the paying parent stops paying, the Department of Healthcare and Family Services can intercept state and federal tax refunds, suspend driver's and professional licenses, place liens on property, deny passport renewals for debts over $2,500, and offset lottery or casino winnings.
A general roadmap, not legal advice — the right steps depend on your situation and deadlines.
Common questions about child support in Illinois
How is the child support amount decided in Illinois?
Illinois uses the Income Shares Model under 750 ILCS 5/505. Both parents' net incomes are combined and matched to a schedule that shows the typical cost of raising children at that income level. The paying parent's share of that amount is proportional to their share of the combined income. The Illinois Department of Healthcare and Family Services provides a free online estimator to help parents get a general idea of the amount.
When does child support end in Illinois?
Child support generally ends on the child's 18th birthday. If the child is still in high school at age 18, support can continue until the child graduates or turns 19, whichever comes first. Support may also continue for a child who has a permanent disability. A court may separately order parents to help pay for college or vocational school expenses under 750 ILCS 5/513.5, but that is a different type of order.
What happens if a parent does not pay child support?
Illinois has many enforcement tools. The state can intercept federal and state tax refunds, suspend driver's and professional licenses, place liens on property, deny passport applications for past-due support of $2,500 or more, and offset lottery and casino winnings. A court can also hold a non-paying parent in contempt, which can result in jail time. Willful failure to pay support is also a criminal offense under the Illinois Non-Support Punishment Act (750 ILCS 16/).
Can I get child support if the parents were never married?
Yes. Illinois applies the same child support rules regardless of whether parents were ever married. Legal parentage must be established first—either by both parents signing a Voluntary Acknowledgment of Parentage or through a court proceeding under the Illinois Parentage Act of 2015 (750 ILCS 46/). Once parentage is legally established, either parent can seek a support order.
Can a child support order be changed after it is set?
Yes. A court can modify a support order if there has been a substantial change in circumstances, such as a major income change, a change in custody, or a new child in the family. Illinois also allows modification when the current order differs from what the guidelines would produce by at least 20 percent and at least $10 per month. Cases with Department of Healthcare and Family Services involvement are reviewed every three years.
Can Illinois courts order a parent to help pay for college?
Yes. Under 750 ILCS 5/513.5, a court can order one or both parents to contribute to a child's college, vocational school, or professional training costs after the child turns 18. The total amount ordered for undergraduate education generally cannot exceed the cost of attending an Illinois public university. A petition for educational support must be filed with the court.
What if the other parent lives in a different state?
Illinois follows the Uniform Interstate Family Support Act, which allows states to work together to establish and enforce support orders across state lines. The Illinois Department of Healthcare and Family Services can coordinate with the other state's child support agency. The federal Personal Responsibility and Work Opportunity Reconciliation Act also requires all states to cooperate on interstate child support cases.
Not legal advice. State-specific statutes, deadlines and procedures are being sourced and will appear here.