Can I Change a Child Support Order in Illinois? | IL Lawyer

 Posted on May 10, 2026 in Child Support

You can change a child support order in Illinois, but you have to show the court that something significant has changed since the original order was put in place. Courts do not modify child support just because one parent wants a different amount. There has to be a real change in circumstances that justifies taking another look at the order. If your financial situation or your child's needs have changed in 2026, a McHenry County, IL child support lawyer can help you figure out whether you have grounds to ask for a modification and what steps to take.

What Does Illinois Law Say About Modifying Child Support?

Under 750 ILCS 5/510, a child support order can be modified when there has been a substantial change in circumstances. Illinois law also allows for a review every three years if the order was entered or last modified before that review period. In those cases, you may not need to show a traditional substantial change if applying the current guidelines would result in a significant difference in the support amount.

The three-year review option is something many parents do not know about, and it can be a straightforward way to get an updated order without having to prove a major life change.

What Counts as a Substantial Change in Circumstances for Child Support Modification in IL?

A substantial change in circumstances means something meaningful has shifted since the last order was entered. It has to be significant enough that the original order no longer reflects the reality of either parent's situation or the child's needs. Common examples include:

• A major increase or decrease in either parent's income

• Job loss or a significant reduction in work hours

• A change in the child's medical needs or health-related expenses

• A change in how much time each parent spends with the child

• The child becoming emancipated or aging out of support

• A significant increase in the cost of raising the child

A small or temporary change in income is generally not enough on its own. Courts look at whether the change will be long-lasting and significant enough to warrant adjusting the support amount.

Can Child Support Be Increased or Only Decreased in Illinois?

Child support can be increased or decreased. Either parent can ask for a modification, and the result can go either way depending on the facts. If the paying parent's income has gone up significantly, the receiving parent may have grounds to ask for an increase. If the paying parent lost his or her job or took a major pay cut, he or she may have grounds to ask for a decrease.

The court looks at both parents' current financial situations when deciding what the new amount should be. Illinois uses an income shares model, which takes both parents' incomes into account, along with the amount of time each parent spends with the child.

What if the Other Parent Agrees to a Change in Child Support?

If both parents agree on a new support amount, the process is simpler. You can submit a written agreement to the court for approval. The court will review it to make sure the new amount is in the best interest of the child before signing off. Even when both parents agree, the change has to be approved by a judge to be legally enforceable. A verbal agreement between parents is not enough.

Skipping the court approval step is a common mistake. If the paying parent simply starts paying a different amount based on an informal agreement and the receiving parent later decides to enforce the original order, the paying parent could end up owing back support.

How Do You File for a Modification of Child Support in Illinois?

To ask for a child support modification in Illinois, you file a petition with the court that issued the original order. The petition explains what has changed and why the current order should be modified. The other parent will be notified and given a chance to respond. If the parents cannot agree on a new amount, the court will hold a hearing and make a decision based on the evidence presented.

Having organized documentation of your current income, expenses, and any changes in your situation makes the process go more smoothly and strengthens your case.

Contact Our Kane County, IL Child Support Attorney Today

Changing a child support order is not always complicated, but it does require following the right legal process from start to finish. The McHenry County, IL child support lawyer at Thomas Law Office has been serving families in the area since 1996. He brings decades of experience helping parents navigate child support modifications with clarity and care. Whether your situation calls for a straightforward modification or a more complicated hearing, he is ready to guide you through every step. Call 847-426-7990 to discuss your situation and learn about your options.