Reviewed August 2026
Child Support in Illinois
Illinois calculates child support under the income shares model. This model comes from 750 ILCS 5/505. The statute tells the Illinois Department of Healthcare and Family Services to adopt a schedule of basic child support obligations. That schedule reflects what parents living together typically spend on their children, based on their combined net income. Illinois circuit courts decide child support in a dissolution of marriage, legal separation, or parentage case. The Department of Healthcare and Family Services' Division of Child Support Services is the state's IV-D agency. It helps parents apply for services, estimate payments, and enforce existing orders.
Virdix's document-preparation product currently prepares divorce paperwork for California and Florida cases. This page explains how child support works under Illinois law for people researching before they file. It is not legal advice, and Virdix does not prepare or file Illinois paperwork. See how Virdix works for California divorces.
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The income shares guidelines under 750 ILCS 5/505
Illinois moved to an income shares model in 2017. The court adds up each parent's monthly net income to get a combined monthly net income. It then looks up the basic child support obligation on the state's published schedule, using that combined income and the number of children. Each parent then pays a share of that obligation based on their share of the combined net income. The goal is simple: support should match what the child would have gotten if the parents and child lived together.
Applying through HFS
The Illinois Department of Healthcare and Family Services' Division of Child Support Services is the state's IV-D agency. You can apply for services online. The department's online portal lets you manage your case, make electronic payments, and use an online child support calculator or estimator built around the income shares schedule. The division also runs regional offices for parents who need in-person help.
Who hears an Illinois child support case
Illinois circuit courts decide child support matters. The case can come from a dissolution of marriage, legal separation, declaration of invalidity of marriage, dissolution of a civil union, or a parentage action. The court applies the 750 ILCS 5/505 guidelines to the parents' documented net income to reach the basic child support obligation. It can also order separate support for post-secondary education needs and for extraordinary medical or child care costs.
Modifying an existing order
You can modify an Illinois child support order under 750 ILCS 5/510. This requires showing a substantial change in circumstances since the order was entered. The Division of Child Support Services also reviews IV-D cases periodically, checking whether the current order still matches the guidelines. You can request that review, or file directly in circuit court for a modification.
Enforcement tools
750 ILCS 5/505 ties nonpayment of child support to contempt of court. Its title reflects this: a parent who willfully fails to pay can face contempt proceedings and penalties. The Division of Child Support Services can also pursue income withholding and intercept state and federal tax refunds. Its online services and forms help you request enforcement of an existing order.
Sources: 750 ILCS 5/505 (Child support; contempt; penalties), Illinois HFS, Child Support
Not independently confirmed
- Exact text and numeric threshold of the 750 ILCS 5/510 modification standard
- Direct URL of the online child support calculator/estimator tool referenced on the HFS child support page
Child Support in Illinois: frequently asked questions
Does Illinois use the income shares model for child support?+
Yes, since a 2017 change to 750 ILCS 5/505. The court combines both parents' monthly net income, then looks up the basic child support obligation on the state's published schedule using that combined income and the number of children. It then divides the obligation according to each parent's share of the combined income.
How do I apply for child support services in Illinois?+
You apply through the Illinois Department of Healthcare and Family Services' Division of Child Support Services. It offers an online portal, electronic payments, an online calculator or estimator, and regional offices for in-person help.
What court hears child support cases in Illinois?+
Illinois circuit courts decide child support cases. These arise from a dissolution of marriage, legal separation, civil union dissolution, or parentage case. The court applies the 750 ILCS 5/505 income shares guidelines to the parents' documented net income.
When can I modify my Illinois child support order?+
Under 750 ILCS 5/510, you generally need to show a substantial change in circumstances since the existing order was entered. The Division of Child Support Services also reviews IV-D cases periodically. You can request that review as an alternative to filing directly in circuit court.
What happens if a parent stops paying child support in Illinois?+
750 ILCS 5/505 authorizes contempt of court proceedings and penalties for a parent who fails to pay. The Division of Child Support Services can also pursue income withholding and intercept state and federal tax refunds to collect unpaid support.
Is there an official Illinois child support calculator?+
Yes. The Department of Healthcare and Family Services offers an online child support calculator or estimator built around the current income shares schedule. You can find it through its child support services website.
This page is general information about child support in Illinois, not legal advice for your situation. Laws, fees, and procedures change over time; confirm current details with Illinois's own courts before relying on anything here. Virdix is not a law firm and is not licensed to practice law in Illinois. Virdix does not prepare or file Illinois divorce paperwork. It is not a substitute for an attorney licensed in Illinois.
More Illinois divorce guides
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In the states Virdix serves, it guides you through that state's own court forms so your paperwork is complete and consistent before you file. If you're filing in Illinois, the resources above are the right place to start, and the form above will tell you the moment Virdix reaches your state.
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