Understanding Child Support: How Courts Calculate Payments and Modify Orders

By Smolka Law Group
Printed child support agreement with man, woman and child wooden figures

Child support is a fundamental component of making sure that the well-being of children after the separation or divorce of their parents. In Illinois, child support laws are structured so that children continue to receive financial support from both parents, even if they no longer live together.

Whether you're establishing child support for the first time or seeking to modify an existing order, it's important to understand how the system works, what factors influence payment amounts, and what the process entails. At Smolka Law Group in Palatine, Illinois, our family law attorneys are ready to help you better understand and establish child support.

The Legal Foundation of Child Support in Illinois

Child support in Illinois is governed by the Illinois Marriage and Dissolution of Marriage Act (IMDMA), specifically 750 ILCS 5/505. The statute outlines the obligations of parents, the method of calculating support, and procedures for enforcement and modification. Illinois follows an "income shares" model, which considers the combined income of both parents to determine how much support a child should receive.

Who Pays Child Support?

Generally, the non-custodial parent - the parent who spends less time with the child - is required to pay child support to the custodial parent, who has the majority of parenting time. However, if parents share equal parenting time, support may still be ordered based on the differences in their incomes and the cost of raising the child.

In Illinois, both parents have a legal responsibility to contribute to the financial support of their children, but the actual payment obligation typically falls to the parent with less residential time or significantly higher income. Our attorneys can help you understand how this might play out in your situation and what child support responsibilities you should expect.

Calculating Child Support Using the Income Shares Model

Since 2017, Illinois has used the income shares model to calculate child support. This model looks at the combined adjusted net income of both parents and uses economic data to determine the basic amount of support the child would have received if the parents were together. Here’s a step-by-step breakdown of this calculation:

1. Determine Each Parent’s Net Income: Net income is calculated by taking gross income (all sources of income, including wages, bonuses, commissions, self-employment income, investment returns, etc.) and subtracting specific deductions. These may include:

  • Federal and state income taxes

  • Social Security and Medicare taxes

  • Mandatory union dues

  • Health insurance premiums for the parent

  • Previously ordered child support for other children

2. Combine Net Incomes: Once both parents’ net incomes are determined, they’re combined to establish the total household income available to support the child.

3. Refer to the Illinois Child Support Guidelines Schedule: The Illinois Department of Healthcare and Family Services (HFS) publishes an official Income Shares Schedule Based on Net Income, which shows the expected monthly child support obligation based on total income and number of children.

4. Determine Each Parent’s Share: Each parent is responsible for a proportional share of the total obligation, based on their percentage of the combined income. For instance, if Parent A earns $4,000 per month and Parent B earns $2,000, Parent A contributes 66.6% of the income and would therefore be responsible for 66.6% of the $1,500—i.e., $999/month.

5. Adjust for Parenting Time: Illinois law allows for adjustments based on shared parenting, which is defined as each parent having the child for at least 146 overnights per year. In this case, a multiplicative formula is used to account for time spent with the child. This can reduce (or in some cases increase) the amount of child support paid.

What Expenses Are Covered by Child Support?

Child support is meant to cover the basic needs of the child, such as food, clothing, housing, transportation, and basic education costs. However, courts may order additional expenses to be shared, such as medical expenses, childcare expenses necessary for a parent’s employment, school fees, extracurricular activities, and other enrichment costs

Deviating from the Guidelines

While the income shares model provides a guideline, Illinois courts recognize that no formula can perfectly fit every family situation. As such, courts may deviate from the guideline amount if there is a valid reason. Any deviation must be justified with a written explanation by the court detailing why the guideline amount is inappropriate.

When deviating from the guidelines, the court must show how the adjusted amount better serves the child’s best interests. This might be due to the child having extraordinary medical or educational needs, one parent having significant travel expenses related to parenting time, or the paying parent having other child support obligations, among other reasons.

Modifying Child Support Orders

Life changes, and with it, so can the ability of parents to pay child support, or the needs of the child. Illinois law allows for the modification of child support orders under specific circumstances. Our family law attorneys can help you determine if your change in circumstances is reason to request a modification from the court.

When Can You Modify Child Support?

You can request a modification if there is a substantial change in circumstances, such as a change in either parent’s income, a change in the child’s needs, a change in parenting time, loss of employment, or a new child from a different relationship. Under Illinois law, child support orders can be reviewed every three years, even without a substantial change in circumstances.

How to Request a Modification

To modify child support, a parent must file a petition to modify in the same court that issued the original order. Both parties will need to disclose updated financial information and may be required to attend a hearing. The court will evaluate whether the modification is warranted and if so, issue a new order.

It’s important to note that modifications are not retroactive - they only take effect from the date the petition is filed, not the date of the change in circumstances. This is why prompt action is essential if your situation changes. If you’ve had a change in circumstances that requires child support modification, contact our office immediately for assistance from one of our attorneys.

Enforcement of Child Support Orders

Failing to pay child support is a serious legal issue. If you’re unable to pay your required child support amount, it’s important to speak with one of our family law attorneys as soon as possible. The Illinois Division of Child Support Services (DCSS) and the courts have a variety of tools to enforce payment, including:

  • Wage garnishment

  • Intercepting tax refunds

  • Suspending driver’s or professional licenses

  • Seizing bank accounts

  • Contempt of court proceedings (which may result in fines or jail time)

If the parent who owes support moves to another state, the Uniform Interstate Family Support Act (UIFSA) makes sure that Illinois child support orders can still be enforced across state lines. If you’re the parent who has not been receiving the child support owed to you, our family attorneys can help. Contact our firm today to find out more about your next steps.

Speak With a Skilled Family Law Attorney Today

Establishing child support in Illinois can be an intricate and emotional process, but understanding how the system works empowers parents to make informed decisions that prioritize the best interests of their children. At Smolka Law Group in Palatine, Illinois, our family law attorneys have the knowledge needed to guide you through the child support establishment process. Reach out to our office today to schedule your consultation and begin working with one of our lawyers.