What is Post-Decree Child Support Modification In Illinois?

 Posted on January 14, 2026 in Child Support

cEven if your 2026 divorce arrangements go well, life continues to change. Jobs shift, children grow, and financial situations change. Illinois law understands this and allows parents to modify child support orders when needed.

"Post-decree child support modifications" refers to changes in child support payments after your divorce is finalized. "Post-decree" simply means anything that happens after the final order is signed.

Our DuPage County child support lawyers help parents navigate post-decree child support. Whether you need to modify an existing order or enforce payments, we can guide you through the process.

When Can Child Support Be Modified After Your Divorce?

Post-decree child support most commonly involves several different types of actions:

• Court enforcement of unpaid child support through arrears (late payment) collection, contempt proceedings, or wage garnishment when payments are not made.

• Adjustments to an existing child support order for "substantial change in circumstances" like job loss, a significant income drop or increase, or a new disability.

• Changes in parenting time that affect support obligations.

• Updates to cover a child's new medical, educational, or special needs.

• Ending or changing support when a child turns 18 or graduates from high school.

How Often Can a Child Support Order Be Changed in Illinois?

Changes to the order can happen whenever there is a "significant change in circumstances." An order might change because one parent becomes disabled, and then change again because the other parent is not paying their child support. An order could be changed yet again because a child develops a serious health issue.

Courts can review child support orders every three years per Illinois law 750 ILCS 5/510, but sometimes things come up before the three year mark that need to be addressed. Parents who want to change orders must submit a request to the court that made the original order.

What is the Most Common Reason for Modifying Orders in Illinois?

The most common reason for child support orders to be modified is a substantial change in circumstances. The most common substantial change in circumstances is job-related. If a parent is suddenly making much less money because of a job loss or pay cut, it is not reasonable for them to keep paying the same amount of child support.

Bear in mind that this can also work the other way. If a parent gets a major raise, it makes sense that they pay an increased amount for the care of their child, especially if their co-parent is at a lower-paying job.

Parents do not automatically have to pay more child support if they get a raise. The court does not magically find out about parents making more or less money the moment it happens. If either parent asks the court for a review, both will have to submit up-to-date financial information (pay stubs, W-2s, financial affidavits, etc.). Even then, a parent with increased income will not necessarily be obligated to pay more. It all depends on what the judge decides is in the child’s best interests.

How Does the Child Support Modification Process Work?

Post-decree child support modifications are handled in two ways in Illinois:

• The Illinois Division of Child Support Services: This agency handles administrative reviews, which are the standard three-year reviews.

• The court system: Some cases are straightforward. Others are more complex and should be handled with help from a lawyer.

If your child's other parent asks to review child support payments, the court will notify you. Within 30 days of receiving a request, the agency or court will send a letter saying whether it qualifies for review. If it does, both parents must provide financial documents to the agency or court.

Once the review process is complete, you will receive a letter saying whether your payments will change. If you disagree with the decision, Illinois law allows you to challenge it. Acting quickly is important because there are time limits for filing appeals or objections.

Call a Plainfield Child Support Attorney Today

Navigating post-decree child support can be complicated. Whether you are seeking to modify an existing order or need help enforcing payments, having an attorney makes a difference.

The DuPage county child support lawyers at The Law Offices of Robert F. Kramer, Ltd. have over 40 years of experience are ready to guide and support you through this process. Contact us today at 630-785-2400 for a free 30-minute consultation.