Life changes after divorce. When circumstances shift substantially, you may be able to modify child support, custody, or maintenance.
To modify a divorce judgment in Illinois, you must show a substantial change in circumstances that was not anticipated when the original order was entered. The change must be:
Can be modified upon substantial change in either parent's income or the child's needs.
Can be modified when in the child's best interests after substantial change.
Reviewable maintenance can be modified. Fixed-term typically cannot.
File in the same court that entered the original judgment. Explain the substantial change and what modification you're seeking.
Your ex must be properly served with the petition. They'll have time to respond and contest the modification.
Exchange financial documents, take depositions if needed. For custody modifications, a GAL may be appointed.
Present evidence of the substantial change. If both parties agree, prove-up the agreed modification. If not, argue your case.
If granted, the court enters a new order. Modifications are prospective only - effective from filing date, not retroactive.
No Retroactive Modifications: Support modifications take effect from the date you file, not before. Don't delay - every month you wait is money you can't recover.
Custody 2-Year Rule: To modify allocation of parental responsibilities (major decisions), you generally must wait 2 years unless the child's present environment seriously endangers them.
File Promptly: When circumstances change, file immediately. Courts are suspicious of delayed filings - they wonder if the change was really that substantial.
Whether you need to modify support, custody, or maintenance - or defend against a modification - understanding the substantial change standard is crucial.