Child Support
How is child support calculated in Illinois?
Illinois uses an income shares model to calculate child support. Rather than relying solely on the paying parent's income, the calculation considers both parents' net incomes and the estimated cost of raising a child.
The parents' combined net income is applied to the Illinois Schedule of Basic Child Support Obligations. Each parent's share of the obligation is then determined according to their proportion of the combined income.
Parenting time may also affect the calculation. Under the law applicable through December 31, 2026, a special shared-care calculation generally applies when each parent exercises at least 146 overnights annually.
Beginning January 1, 2027, Illinois will lower the shared-care threshold to 110 overnights, with additional adjustments for parenting schedules involving fewer than 146 overnights.
Other expenses, including health insurance and childcare, may also affect the final support obligation.
750 ILCS 5/505 – Child Support and Public Act 104-0733 – Changes Effective January 1, 2027.
What counts as income for child support purposes in Illinois?
Illinois defines income broadly when calculating child support.
Income may include wages, salaries, bonuses, commissions, tips, self-employment earnings, rental income, investment income, retirement benefits, unemployment compensation, and certain other payments.
However, not every payment or financial benefit necessarily qualifies as income. Illinois law excludes certain benefits and requires specific adjustments when calculating net income.
For parents who are self-employed or own businesses, determining income may require reviewing business expenses, distributions, retained earnings, and other financial records.
Courts may also attribute income to a parent who is voluntarily unemployed or underemployed, subject to the requirements of the statute. The court may consider employment history, qualifications, earning capacity, and available employment opportunities.
At LaRocque Law, we focus on identifying the income actually available for support rather than relying exclusively on the amount reported on a financial affidavit or tax return.
750 ILCS 5/505(a)(3) – Income and Child Support Calculations.
Can parents agree to waive child support in Illinois?
Parents generally cannot permanently waive a child's right to financial support through a private agreement.
However, that does not mean every case must result in one parent making monthly child support payments to the other. Depending on the parents' incomes, parenting arrangement, and the child's financial needs, the appropriate support obligation may be reduced, offset, or, in some circumstances, set at zero.
Illinois courts must determine whether a proposed child support arrangement complies with the law and serves the child's interests.
Parents may negotiate support terms, but an agreement that differs from the statutory guidelines generally requires appropriate findings and court approval.
Even when parents agree on support, the court retains authority over child support matters, including modification when the statutory requirements are met.
750 ILCS 5/505(a)(2) – Child Support Guidelines and Deviations.
What can I do if the other parent stops paying child support?
If the other parent stops paying court-ordered child support, you may have several enforcement options.
Depending on the circumstances, enforcement may include:
Income withholding from wages
A petition for rule to show cause
Collection of unpaid support and applicable interest
Liens against certain assets
Interception of eligible tax refunds
License suspension or other administrative enforcement remedies
Unpaid child support generally becomes an enforceable obligation as installments come due. A parent's failure to pay does not automatically eliminate the underlying debt.
Contempt may be available when the court determines that a parent willfully failed to comply with a support order despite having the ability to do so.
At LaRocque Law, we evaluate the amount owed, the paying parent's financial circumstances, available assets, and the likely effectiveness of enforcement before recommending a particular approach.
750 ILCS 5/505 – Child Support and Enforcement and 750 ILCS 5/510 – Modification and Termination.
What is the Illinois State Disbursement Unit?
The Illinois State Disbursement Unit, commonly called the SDU, is the centralized payment processing system used to collect and distribute child support payments.
When payments are processed through the SDU, the paying parent or employer submits the payment, and the SDU processes and distributes the funds to the appropriate recipient.
The SDU also maintains payment records, which can be important when determining whether support has been paid or whether arrearages exist.
However, SDU records may not reflect every payment that a parent claims to have made, particularly if payments were made outside the required system.
For that reason, both parents should maintain their own records and verify that payments are being properly credited.
750 ILCS 5/507.1 – Payment of Support to State Disbursement Unit.
Do all child support payments have to go through the State Disbursement Unit?
Not necessarily. The required payment method depends on the support order and whether income withholding or state child support enforcement services are involved.
When payments are made through income withholding, they generally must be directed to the State Disbursement Unit.
Payments are also generally required to go through the SDU when a party receives qualifying child support enforcement services.
In other circumstances, the court order may direct payments through another authorized method.
Parents should not assume that direct payments between them will automatically receive credit toward a court-ordered support obligation.
Before making payments outside the designated system, review the judgment and any applicable income withholding order. Maintaining a clear payment record is especially important when support obligations continue for many years.
750 ILCS 5/507.1 – Payment of Support.
What is an income withholding order for child support?
An income withholding order, often called an IWO, directs an employer or other payor of income to deduct child support payments from the obligated parent's income.
The withheld funds are generally sent to the Illinois State Disbursement Unit for processing and distribution.
Income withholding is the standard collection method for many Illinois child support obligations and helps establish a consistent payment record.
However, income withholding does not eliminate the paying parent's responsibility to ensure that the correct amount is paid.
If an employer fails to withhold support, withholding is delayed, or the parent's employment changes, the underlying support obligation generally remains enforceable.
750 ILCS 28 – Illinois Income Withholding for Support Act.
How does income withholding for child support work?
Once an income withholding notice is properly issued and delivered to an employer, the employer must begin withholding support in accordance with Illinois law.
The employer deducts the required amount from the employee's eligible income and sends the payment to the State Disbursement Unit.
Illinois law generally requires employers to begin withholding no later than the applicable pay period following the statutory notice period. Employers must also remit withheld funds within seven business days after the date the income otherwise would have been paid to the employee. The State Disbursement Unit then processes and distributes the payment.
If a parent changes jobs or receives income from multiple sources, additional withholding notices may be necessary.
The paying parent remains responsible for the full court-ordered obligation, even if withholding has not yet begun.
750 ILCS 28/35 – Duties of an Income Payor.
What happens if an employer does not comply with a child support income withholding order?
Illinois employers are legally required to comply with properly issued income withholding notices. An employer that knowingly fails to withhold or remit the required support may face statutory penalties.
Under the Illinois Income Withholding for Support Act, an employer may be subject to a penalty of $100 per day for certain knowing failures to withhold or remit support after the applicable deadline, subject to statutory limitations.
If you are not receiving support payments, or your employer has not implemented a withholding notice, the first step is to determine whether the notice was properly served and whether the employer has complied with its obligations.
Importantly, an employer's failure to withhold does not ordinarily cancel the paying parent's support obligation.
750 ILCS 28/35 – Employer Duties and Penalties.
What percentage of income is child support in Illinois?
Illinois no longer calculates child support using a fixed percentage of one parent's income.
Before July 1, 2017, Illinois generally used percentages such as 20% for one child and 28% for two children.
Today, Illinois uses an income shares model that considers both parents' net incomes, the number of children, the applicable support schedule, and the parenting arrangement.
This means two families with the same paying parent's income may have different support obligations depending on the other parent's income and the circumstances of the case.
There is no single percentage that applies to every Illinois child support calculation.
750 ILCS 5/505 – Income Shares Child Support Guidelines.
When does child support end in Illinois?
Illinois child support generally terminates when a child turns 18, subject to applicable statutory exceptions and the terms of the support order.
If the child turns 18 while still attending high school, support generally continues until graduation or the child's 19th birthday, whichever occurs first.
However, it is important to review the actual judgment before stopping payments. The order may contain specific termination provisions, and additional procedures may be necessary, particularly when support is owed for multiple children.
Unpaid child support does not disappear simply because the current support obligation ends.
Illinois also permits courts to order certain expenses beyond the child's eighteenth birthday, including educational expenses under Section 513 and support for qualifying non-minor children with disabilities under Section 513.5.
750 ILCS 5/510(d) – Termination of Child Support, 750 ILCS 5/513 – Educational Expenses, and 750 ILCS 5/513.5 – Support for a Non-Minor Child with a Disability.
Do divorced or unmarried parents have to pay for college in Illinois?
Possibly. Illinois law permits courts to order parents to contribute toward certain educational expenses for a non-minor child.
Under 750 ILCS 5/513, qualifying expenses may include tuition, fees, housing, meals, books, supplies, and certain other educational costs.
The court considers factors such as the financial resources of both parents, the child's resources, the child's academic performance, and the standard of living the child would have enjoyed had the marriage not been dissolved.
The statute also establishes limitations, including a general cap on certain educational expenses tied to the University of Illinois at Urbana-Champaign, unless the parents agree otherwise.
The child generally must maintain at least a C average, subject to statutory exceptions.
Educational expense obligations ordinarily terminate upon graduation, attainment of age 23, or another applicable statutory event, although support may extend to age 25 for good cause.
College expenses are separate from ordinary child support and should be considered when negotiating a divorce or parentage judgment.
750 ILCS 5/513 – Educational Expenses for a Non-Minor Child.
How do I file for child support in Illinois?
There are several ways to seek child support in Illinois, depending on your circumstances.
One option is to apply for services through the Illinois Department of Healthcare and Family Services, which can assist eligible parents with establishing parentage, obtaining support orders, and enforcing existing obligations.
Another option is to request child support through a court proceeding, often as part of a divorce, parentage, or related family law case.
If parentage has not been legally established, that issue may need to be addressed before a support order can be entered.
A private attorney can also assist with related issues such as parenting time, allocation of parental responsibilities, financial discovery, and contested hearings.
The appropriate approach depends on whether a court case is already pending, whether parentage is established, and the issues that need to be resolved.
750 ILCS 5/505 – Child Support and Illinois Department of Healthcare and Family Services – Child Support Services.
Can child support be stopped or canceled in Illinois?
Child support cannot ordinarily be terminated simply because the parents informally agree that payments are no longer necessary.
A support obligation remains governed by the applicable court order and Illinois law.
If circumstances have changed, a parent may seek modification or termination of support through the appropriate legal procedure.
Examples include a qualifying change in the child's residence, a significant change in income, emancipation, or another event recognized under Illinois law.
Some termination events occur by operation of law or pursuant to the express terms of the judgment. Others require additional court action.
Importantly, terminating current support does not ordinarily eliminate child support arrearages that accrued before termination.
Before stopping payments, the paying parent should confirm the legal effect of the existing order and whether further court action is necessary.
750 ILCS 5/510 – Modification and Termination of Support.
How can I modify child support in Illinois?
Either parent may request a modification of child support when the applicable statutory requirements are satisfied.
Under 750 ILCS 5/510, child support generally may be modified upon a substantial change in circumstances.
Examples may include:
A significant increase or decrease in income
A change in employment or earning capacity
A substantial change in parenting arrangements
Changes in the child's financial or healthcare needs
Other circumstances affecting the appropriate support obligation
Certain cases receiving child support enforcement services may also qualify for modification under additional statutory provisions without demonstrating a substantial change in circumstances.
Timing matters. Child support modifications generally apply only to installments accruing after the required notice of the modification request.
This means that waiting to file can have significant financial consequences, even when the underlying circumstances changed months earlier.
Until the order is legally modified, the existing support obligation generally remains enforceable.
750 ILCS 5/510(a) – Modification of Child Support.
What expenses does child support cover in Illinois?
Basic child support is intended to contribute toward a child's ordinary living expenses, including housing, food, clothing, and other everyday needs.
However, the basic child support amount does not necessarily address every expense associated with raising a child.
Illinois courts may separately allocate additional expenses, including:
Health insurance premiums attributable to the child
Uncovered medical and dental expenses
Work-related childcare expenses
Certain school and educational expenses
Extracurricular activities
Other expenses permitted under Illinois law
The allocation of these expenses depends on the statute, the parents' financial circumstances, and the terms of the support order.
A well-drafted child support order should clearly identify which expenses are included in basic support, which are shared separately, and how reimbursement requests must be handled.
This can reduce future disagreements over expenses that neither parent anticipated when the order was entered.
750 ILCS 5/505 – Child Support and Additional Expenses.
Does 50/50 parenting time eliminate child support in Illinois?
No. Equal parenting time does not automatically eliminate child support.
Illinois considers both parents' incomes when determining support. As a result, even when parents exercise equal parenting time, one parent may still owe child support if there is a significant difference in income.
Under the law applicable through December 31, 2026, the shared-care calculation generally applies when each parent exercises at least 146 overnights annually.
Beginning January 1, 2027, the statutory shared-care threshold will decrease to 110 overnights, with additional adjustments based on the amount of parenting time exercised.
In shared-care cases, the calculation accounts for both parents' financial contributions and the time the child spends in each household.
Equal parenting time and similar incomes may produce a relatively small support obligation, but a zero-dollar result is not guaranteed.
The calculation may also be affected by health insurance, childcare, and other applicable expenses.
750 ILCS 5/505(a)(3.8) – Shared Physical Care and Public Act 104-0733 – Effective January 1, 2027.
Is there an Illinois child support calculator I can use?
Yes. Our Illinois Child Support Calculator can help you estimate child support using the Illinois income shares guidelines.
The calculation considers both parents' incomes, the number of children, and the applicable parenting arrangement.
However, a calculator is only a starting point.
The actual support obligation may depend on additional factors, including:
How each parent's net income is determined
Whether income should be attributed to a parent
The number of parenting overnights
Health insurance premiums and childcare expenses
Other applicable statutory adjustments
Whether the court determines that a deviation is appropriate in your case