Child support generally cannot be modified retroactively, pursuant to 750 ILCS 5/510(a).
For example, say a child support payor is incarcerated but had been ordered to pay child support. That individual would likely be unable to pay child support during his incarceration and he or she would accumulate an arrearage of back child support. Let’s also assume that this individual does not request a modification either before or during his or her incarceration, but instead waits to file a modification upon their release. The Court would not be willing or able to reduce the child support amounts owed during the incarceration and would not grant the modification.
This example highlights the importance of filing a modification for child support as soon as possible in your case. The Court will only consider a modification for “installments accruing subsequent to due notice,” meaning for payments due after the modification is filed. See generally In re Marriage of Pettifer and Mathias, 304 Ill.App.3d 326 (1999).
There are two exceptions to this general rule. 750 ILCS 5/502(f) allows that the parties may agree to a modification of child support. Referring back to the incarceration example, if the parties came to an agreement that reduced the child support arrearage owed for the time period the payor was incarcerated, the Court would have the authority to accept that agreement under the statute.
The Court also has the authority to establish and/or modify any Court order to include an obligation to pay expenses such as deductibles, copayments, and other health expenses, in addition to any costs covered by health insurance. This authority comes from 750 ILCS 5.505.2(b)(3). Therefore, theoretically, the Court could order or “modify” these support payments retroactively.
In light of these limitations, it is important to speak with an attorney as soon as you feel a modification is appropriate in your case.