When can you modify the terms of a divorce judgment?

Short answer: you probably cannot modify your property settlement provisions, but you might be able to modify the parts of your divorce judgment that relate to your kids.

A divorce judgment is a final judgment under Illinois law. It cannot generally be modified. In particular, the parts of the divorce judgment that have to do with dividing money or property can almost never be modified after the fact. The only way they can be modified is if both parties agree.

In contrast, child support, spousal maintenance, and allocation of parental responsibility (what used to be called custody and visitation) can be modified if either parent shows a "substantial change in circumstances." This is because the law in Illinois recognizes that decisions made about child support, spousal maintenance, or allocation of parental responsibility may change over time. Therefore, the party who wants to modify the divorce judgment has to show the court that such a change is warranted, because the circumstances have substantially changed from when the original divorce judgment was entered.