Child Support Modification in Illinois

This article provides an overview of child support modification laws in Illinois.

Overview of Illinois Child Support Laws

When parents decide to divorce (or separate if they were never married), they’ll need to figure out many child-related issues, including who will pay child support and how much will be paid.

In Illinois, child support is calculated using the Illinois Child Support Guidelines, which set forth a formula that judges must follow in order to set the proper amount of child support. Generally speaking, the calculation is completed by applying a specific percentage to the non-custodial parent’s net income; the exact percentage applied will depend on the number children supported.

Parents can try to agree on child support, but if they can’t agree, they will end up in court where a judge will decide. However, even if parents enter into a child support agreement, a judge will need to review it and make sure it provides for, at a minimum, the guideline amount under the law. Parents can’t just agree to child support that doesn’t at least meet the guidelines.

For more information on how courts calculate child support, see Child Support in Illinois, by Susan Bishop.

How is Child Support Modified in Illinois?

In Illinois, child support continues until a child turns 18 or graduates from high school, whichever occurs later. So, once a child support order has been issued by a court (whether it was obtained by an agreement or court hearing) the paying parent must continue paying the amount stated in the order until the child turns 18 or graduates from high school, unless a court grants a modification (change) to the support amount.

As with the original child support amount, parents can agree to modify child support and submit a request that the court approve their proposed change. If the agreement meets state standards, the judge will issue new orders. If the new agreement does not satisfy Illinois law, parents will have to adjust their agreement.

If parents simply can’t agree on a proper modification amount, a judge will have to determine whether child support should be modified, and if so, by what amount. But this won’t just happen automatically; the parent requesting the change will need to file a “motion” or “petition” (legal paperwork) asking a court to change child support and identifying the reasons it should be changed.

Generally, a court will not modify a child support order unless the parent requesting a change can show one of the following:

  • an ongoing and substantial change in circumstances, such as a change in either parent’s income, expenses, geographical location, or health insurance rates, or
  • a 20% difference between the amount of the existing child support order and the amount that would result from a current and updated application of the guidelines (this applies only in cases where a parent is receiving child support enforcement services from the Department of Healthcare and Family Services and only when at least 36 months have elapsed since the first child support order was entered or last modified), or
  • a need to provide the for the health care needs of a child under the order through health insurance or other means.

Should I Hire an Attorney?

Child support laws and guidelines can be complicated. On the surface, the calculations appear to be simple, but a closer look reveals some confusing elements, which may require a bit more expertise to understand. If you have questions about calculating child support, you should contact an experienced family law attorney for help.

It may be even more important to have expert legal help when attempting to modify a child support order. Parents who are considering modifying already existing support orders should contact an attorney to be sure their rights are protected and they are in compliance with Illinois laws.

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