How Long Child Support Modifications Take in Illinois

 Posted on September 28, 2025 in Child Support

Child support orders are not permanent. Over time, you may face job changes, shifts in your parenting schedule, or new expenses for your children. The amount paid or received is based on your income, the other parent’s income, and the current parenting time schedule. When your circumstances change, the court allows you to request a modification. The amount of time it takes to get that modification can vary depending on many factors.

At The Law Office of Matthew M. Williams, P.C., our DeKalb County, IL child support lawyers have experience walking parents through the modification process. During your free initial consultation, we will review your situation and discuss the steps you should take first.

When Can You Modify Child Support in Illinois?

Under Illinois law (750 ILCS 5/510), child support can be modified if there is a "substantial change in circumstances." This can describe a wide range of incidents. However, it generally refers to an important, typically unanticipated, shift in your situation that makes the current order unfair or unworkable.

Common reasons to request a modification include:

• A parent loses a job or has work hours cut

• A parent develops a disability

• A parent gets a new job, promotion, or salary raise

• The parenting schedule changes in a way that affects overnight stays

• There are new, higher costs for the child’s medical care, childcare, or school

• Illinois child support rules are updated in a way that changes how payments are set

• A parent remarries and the household’s finances change

• A child turns 18 or is legally considered independent

• Health insurance changes raise or lower costs

How Long Does It Usually Take To Change Child Support in Illinois?

On average, it can take a few months from when you file for a child support modification to be approved in a final order. The initial waiting period for a hearing to determine whether there has been a substantial change in circumstances can take as long as 30 days. However, cases can generally move faster when both parents cooperate, and the paperwork is complete.

In certain cases, the court may move faster if the situation is straightforward and both parents provide complete information. Some situations call for only short-term adjustments, while others require longer-lasting changes, which the court addresses differently. Our attorneys will review your circumstances and set clear expectations for how long the process is likely to take.

What Is the Difference Between Temporary and Permanent Child Support Modifications?

Temporary orders deal with short-term changes, such as surgery recovery or seasonal layoffs. These orders can be adjusted back once the situation improves. Permanent modifications apply to long-term changes, like a new job, a lasting disability, or a major shift in parenting time.

How Does the Child Support Modification Process Work?

You start the modification process by filing a motion with the same court that issued your original order. After filing, both you and your co-parent will exchange updated financial affidavits, usually covering the last two years. Judges use these documents to decide whether a change is justified and, if so, how much support should be paid.

Under 750 ILCS 5/505, Illinois courts calculate support using the income-shares model. The judge looks at both parents’ incomes, the number of children covered by the order, and the parenting time schedule. If a modification is granted, the judge enters a new Uniform Order for Support, which is just as enforceable as the original.

Can Illinois Judges Deviate From Child Support Guidelines?

Sometimes the standard formula for child support does not fit a family’s situation. In those cases, Illinois law allows judges to depart from the guidelines when the standard amount would be unfair. They can order more or less than the guideline amount if special circumstances exist. For example, a judge may change the amount if a child has major medical needs, if educational costs are unusually high, or if income is very high or very low. However, they will have to explain the reason for any change in the court order. Each case is looked at individually, and the order stays in place until a new motion is filed.

What Might Cause the Child Support Modification Process To Slow Down?

Delays can occur during the child support modification process for several reasons. Some of the most common include:

• One parent does not provide complete or accurate financial records

• Court schedules are packed, delaying hearing dates

• Parents disagree over income, parenting time, or child-related expenses

• Extra hearings are needed to resolve disputes

• Paperwork is incomplete or filed incorrectly

Our attorneys keep cases moving by meeting every deadline and filing complete, accurate paperwork.

Do You Need To Go Back to Court To Change Child Support in Illinois?

Once child support is set by a court order, only the court can change it. The payment amount and schedule are legally enforceable, and parents cannot alter them on their own. If the paying parent stops paying or pays less than the order requires, they can face serious consequences. This is true even if both parents agreed to the change. Regardless of a job loss or an increase in income, the support amount remains the same until a judge issues a new order.

Can Back Child Support Be Reduced After a Modification?

Illinois law does not allow retroactive reductions to child support. Once a modification is granted, it takes effect only from the date you file your motion. If you lost your job in January but waited until June to file, you still owe the original amount for the months before filing. Acting quickly protects you from building arrears you cannot erase later.

Contact a DeKalb County, IL Child Support Attorney for a Free Consultation Now

At The Law Office of Matthew M. Williams, P.C., we bring more than 25 years of experience to family law matters across Aurora, Naperville, and DuPage County. Our practice emphasizes mediation and collaborative divorce. This approach helps families lower costs and resolve issues in a more respectful and efficient way. When modifications or enforcement actions are necessary, we provide the guidance and advocacy you need. Call 630-409-8184 today to schedule a free consultation with our experienced DuPage County, IL child support modification lawyers.