Child Support Modification - Preparation Worksheet - Illinois
ILLINOIS CHILD SUPPORT MODIFICATION PREPARATION PACKET
Do not file this document. The Illinois Courts page directs a person seeking to change ordered child support to file a motion stating why support should be increased or decreased. Use the current approved statewide Motion, Notice of Court Date, Proof of Delivery, Financial Affidavit, and support-order materials, plus every county-required form.
1. Current-Form and Court Control
| Control item | Completed entry |
|---|---|
| Circuit and county | [________________________________] |
| Existing case number | [________________________________] |
| Original party designations preserved | ☐ Yes ☐ No |
| Assigned judge or calendar, if known | [________________________________] |
| Current statewide forms downloaded on | [__/__/____] |
| County rules, filing method, fees, scheduling, and copies checked on | [__/__/____] |
| Reviewing Illinois attorney | [________________________________] |
The pages accessed August 27, 2026 listed the general Motion, Additional Motion, Notice of Court Date, and filing instructions as approved August 2025; Proof of Delivery as approved September 2025; Financial Affidavit as approved June 2025; and the Order for Support materials as approved September 2025. Recheck every live page and linked form immediately before use.
2. Existing Order and Scope Record
| Item | Record |
|---|---|
| Existing support order date | [__/__/____] |
| Last modification date | [__/__/____] |
| Current ordered amount and frequency | $[________] per [________] |
| Obligor and obligee | [________________________________] |
| Existing guideline calculation and any deviation findings obtained | ☐ Yes ☐ No |
| HFS child-support enforcement services currently received | ☐ No ☐ Yes—evidence: [________________] |
| Requested change limited to child support | ☐ Yes ☐ No—other issue/route: [________________] |
| Existing income-withholding or support order obtained | ☐ Yes ☐ No |
Do not use a generic support motion to add parenting-time, allocation, contempt, arrears enforcement, maintenance, educational-expense, tax, or other relief without selecting and grounding the correct route.
3. Section 510(a) Route Screen
Route A — Substantial Change in Circumstances
☐ Facts claimed as substantial change: [________________________________]
☐ Date each change occurred: [________________________________]
☐ Supporting income, employment, parenting, health, insurance, child-care, or child-needs records: [________________________________]
Route B — HFS 20%/$10 Review Route
Use this route only if every gate is met:
☐ A party is receiving child-support enforcement services from HFS under Article X.
☐ At least 36 months have elapsed since the support order was entered or last modified.
☐ The current guideline amount is inconsistent with the existing order by at least 20% and at least $10 per month.
☐ If the existing order was a guideline deviation, counsel confirmed a change in the circumstances that produced the deviation.
36 months alone is not a modification ground. The 20%/$10 figures are not an alternative joined by “or,” and this administrative-services route is not automatically available in a private case.
Route C — Health-Care Need
☐ Facts showing a need to provide for the child's health-care needs through insurance or other means: [________________________________]
Public Act 99-764 Screen
☐ The motion does not treat enactment of the income-shares changes as a substantial change by itself; counsel recorded any independently supported substantial change: [________________________________]
4. Notice-Date and Requested Effective Date
Section 510(a) limits modification to installments accruing after due notice by the moving party of the filing of the motion. Record the actual filing and notice events; do not assume the change dates back to the underlying facts, a private demand, or drafting date.
| Event | Date | Evidence |
|---|---|---|
| Motion filed | [__/__/____] | [________________________________] |
| Due notice given | [__/__/____] | [________________________________] |
| Earliest requested installment after notice | [__/__/____] | [________________________________] |
| Counsel's effective-date conclusion | [__/__/____] | [________________________________] |
5. Financial and Guideline Workpapers
Use the current statewide Financial Affidavit and additions. This packet performs no support calculation and supplies no income definition, deduction, parenting-time formula, health-insurance allocation, child-care allocation, medical allocation, deviation rule, or tax treatment.
☐ Each party's current Financial Affidavit obtained or requested
☐ Employment, business, pay, tax, benefit, and other-income records reconciled
☐ Existing support and maintenance obligations documented
☐ Health-insurance availability and child-only cost documented
☐ Child-care and health-care expenses documented
☐ Parenting-time inputs and overnight records verified
☐ Existing deviation findings and current claimed deviation facts reviewed
☐ Current official calculator, worksheet, or counsel workpaper identified: [________________________________]
| Calculation control | Entry |
|---|---|
| Existing order amount | $[________] |
| Current calculated amount | $[________] |
| Dollar difference | $[________] |
| Percentage difference | [________]% |
| Route and reviewer | [________________________________] |
6. Motion Drafting Record
Use the current statewide Motion and Additional Motion pages. State facts rather than contract recitals, warranties, defaults, covenants, or remedy menus.
| Motion component | Drafting record |
|---|---|
| Existing order identified | [________________________________] |
| Selected § 510(a) route | [________________________________] |
| Material facts with dates | [________________________________] |
| Requested support amount and frequency | [________________________________] |
| Requested effective date tied to notice analysis | [________________________________] |
| Health-care or insurance request, if grounded | [________________________________] |
| Other relief with separate authority | [________________________________] |
| Exhibits and confidential information review | [________________________________] |
Do not insert automatic income withholding, fees, interest, contempt, license suspension, injunction, prevailing-party, disclosure, asset-restraint, jury, arbitration, severability, integration, indemnity, liability-cap, or electronic-signature conclusions without separate current authority and facts.
7. Notice, Delivery, Filing, and Hearing Control
| Step | Current form or rule | Date/deadline | Completion evidence |
|---|---|---|---|
| Motion and any Additional Motion completed | [________________________________] | [________________________________] | [________________________________] |
| Notice of Court Date completed | [________________________________] | [________________________________] | [________________________________] |
| Filing accepted by circuit clerk | [________________________________] | [________________________________] | [________________________________] |
| Delivery method and recipient confirmed | [________________________________] | [________________________________] | [________________________________] |
| Proof of Delivery completed and filed | [________________________________] | [________________________________] | [________________________________] |
| Financial disclosures exchanged | [________________________________] | [________________________________] | [________________________________] |
| Hearing date, format, and courtroom confirmed | [________________________________] | [________________________________] | [________________________________] |
| Proposed support order materials prepared | [________________________________] | [________________________________] | [________________________________] |
| County-specific step | [________________________________] | [________________________________] | [________________________________] |
8. Evidence and Hearing File
| Issue | Exhibit or witness | Foundation or authenticity | Objection or gap |
|---|---|---|---|
| Existing order and prior calculation | [________________________________] | [________________________________] | [________________________________] |
| Income and employment | [________________________________] | [________________________________] | [________________________________] |
| Insurance and health-care need | [________________________________] | [________________________________] | [________________________________] |
| Child care and other child expenses | [________________________________] | [________________________________] | [________________________________] |
| Parenting schedule | [________________________________] | [________________________________] | [________________________________] |
| HFS services and review date, if used | [________________________________] | [________________________________] | [________________________________] |
| Existing deviation and changed facts | [________________________________] | [________________________________] | [________________________________] |
9. Final Counsel Gate
☐ Current statute page and amendment leads rechecked.
☐ Current statewide forms and county procedure rechecked.
☐ The correct § 510(a) route is pleaded; 36 months is not used alone.
☐ HFS services, 36 months, 20%, $10, and deviation gates are all documented if Route B is used.
☐ Filing, due notice, and requested effective date are separately recorded.
☐ Current financial affidavits and guideline calculations reconcile to source records.
☐ Requested relief is limited to supported issues and the correct forms.
☐ Only current court forms and separately reviewed papers—not this packet—will be filed.
Reviewed by: [________________________________]
Review date: [__/__/____]
This preparation aid is not a court form and must not be filed.
About this template
- Last updated
- August 27, 2026
- Citations checked
- August 27, 2026
- Jurisdiction
- Illinois
- Category
- Family Law
Legal authority
- 750 ILCS 5/510(a) (modification routes and notice-date limit)
Family law covers the paperwork that shapes divorce, custody, child support, adoption, guardianship, and other family matters. These filings are emotional and high-stakes, and they also have to meet strict procedural rules for service, financial disclosure, and parenting plans. Clean, accurate paperwork keeps the focus on getting a workable outcome for the family instead of getting derailed by technical problems that delay hearings or force amended filings.
Not legal advice
This template is provided for informational purposes. We recommend having an attorney review any legal document before signing, especially for high-value or complex matters.
Checked against the law it cites
A reviewer verified this template's legal citations against the official source on August 27, 2026.
750 ILCS 5/510(a) (checked August 27, 2026): "The provisions of any judgment respecting maintenance or support may be modified only as to installments accruing subsequent to due notice by the moving party of the filing of the motion for modification. An order for child support may be modified: (1) upon a showing of a substantial change in circumstances; and (2) without the necessity of showing a substantial change in circumstances, (A) upon a showing of an inconsistency of at least 20%, but no less than $10 per month, between the amount of the existing order and the amount of child support that results from application of the guidelines specified in Section 505 of this Act unless the inconsistency is due to the fact that the amount of the existing order resulted from a deviation from the guideline amount and there has not been a change in the circumstances that resulted in that deviation; or (B) upon a showing of a need to provide for the health care needs of the child under the order through health insurance or other means. The provisions of subparagraph (a)(2)(A) shall apply only in cases in which a party is receiving child support enforcement services from the Department of Healthcare and Family Services under Article X of the Illinois Public Aid Code, and only when at least 36 months have elapsed since the order for child support was entered or last modified. The enactment of Public Act 99-764 itself does not constitute a substantial change in circumstances warranting a modification."
Illinois Courts — changing child support payments (checked August 27, 2026): "If you want to change the amount of child support that has been ordered, you will need to file a motion asking the judge to do that. You can use the Motion forms. You will need to state on the Motion the reason the support should be changed. The form can be used to ask that the support be increased or decreased."
Illinois Courts — statewide Motions and Notice forms (checked August 27, 2026): "The Supreme Court Commission on Access to Justice has approved the following forms. All Illinois Courts must accept these forms. How to File & Send a Motion & Notice of Court Date for Motion — Approved 08/2025. Motion — Approved 08/2025. Notice of Court Date for Motion — Approved 08/2025. Proof of Delivery — Approved 09/2025."
Illinois Courts — statewide Financial Affidavit forms (checked August 27, 2026): "The Supreme Court Commission on Access to Justice has approved the following forms. All Illinois Courts must accept these forms. Financial Affidavit (Family & Divorce Cases) — Approved 06/2025."
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