Child Support Modification Petition in Illinois

Federal & State Law Editorial TeamLast reviewed: April 2026

Illinois Requirements

Substantial change in circumstances OR 20%/$10 deviation from current guideline calculation
Petition to Modify + Financial Affidavit (Income/Expense)
Income shares guideline (use HFS calculator) attached
Service per Supreme Court Rule 105 if other party not represented
Modifications retroactive to date of filing only (no earlier)

Filing Location

Circuit Court (Family Division) in the county of the order

Filing Fee

$70–$340 motion fee (varies by county; waivable for indigent)

Statute Reference

750 ILCS 5/510 (modification of judgment); 305/8a (HFS administrative modification)

How to Complete This Form

1Obtain a blank quitclaim deed form that complies with your state's requirements.
2Enter the full legal name and address of the grantor (the person transferring the property).
3Enter the full legal name and address of the grantee (the person receiving the property).
4Include the complete legal description of the property (obtained from the current deed or county records).
5Sign the deed in the presence of a notary public and any required witnesses.
6File the deed with the county recorder's office along with any required transfer tax forms and fees.
7Keep a copy of the recorded deed for your records.

Download Form Template

Download a template for the Child Support Modification Petition customized with Illinois-specific requirements and instructions.

Child Support Modification Petition in Other States

California Texas Florida New York Pennsylvania Ohio Georgia North Carolina Michigan Alabama Alaska Arizona Arkansas Colorado Connecticut Delaware Hawaii Idaho Indiana Iowa Kansas Kentucky Louisiana Maine

Other Forms in Illinois

Quitclaim Deed Power of Attorney Last Will and Testament Living Will / Advance Directive LLC Operating Agreement Residential Lease Agreement Eviction Notice Small Claims Court Complaint Divorce Petition Name Change Petition Warranty Deed Bill of Sale Prenuptial Agreement Rental Application Demand Letter Affidavit of Service Promissory Note Non-Disclosure Agreement Non-Compete Agreement

When to Talk to a Lawyer

Your situation involves complex legal issues or significant financial consequences.
You are unsure whether the form meets your state's specific requirements.

This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.