How to Fill Out and File Form 4-11: NY Child Support Modification

Form 4-11 is New York’s Petition for Modification of an Order of Support, and you use it to ask a Family Court Support Magistrate to raise or lower an existing child support order. Download the PDF from the New York State Unified Court System website, fill in the case information from your existing order, check the box for the legal ground you’re relying on, and file the completed petition with the Family Court clerk along with a Personal Information Form and a Financial Disclosure Affidavit. There is no filing fee.¹ The petition itself is short. The work is in picking the right ground, assembling your financial records, and getting the papers served correctly.

Pick the Ground That Applies to You

Family Court Act § 451 gives you three independent grounds for modification. You only need one, and paragraph 6 of Form 4-11 asks you to check which:²

A substantial change in circumstances since the last order — a job loss, serious illness, a new special-education or medical need, or a comparable event that makes the current amount unreasonable.
Three years have passed since the order was entered, modified, or adjusted. No other change is required.
Either parent’s gross income has changed by 15 percent or more since the order was last addressed.

Before you check anything, pull out your existing order or settlement agreement and look for an opt-out clause. The three-year and 15-percent grounds are available unless both parties specifically opted out in writing.³ If you opted out, your only path is the substantial-change ground, and you’ll need more documentation to support it.

One catch on income-based petitions: a drop in income only counts if it was involuntary and you’ve made a genuine effort to find comparable work. Quitting or cutting your hours will not get you a lower order. Incarceration, by contrast, is not treated as voluntary unemployment and can qualify as changed circumstances.³

Gather Your Forms and Financial Records First

A complete filing package includes the petition plus two companion forms and supporting financial documents. Missing pieces send you back to the clerk’s office.

The Court Forms

Form 4-11, the petition itself, available as a PDF on nycourts.gov.²
Form 4-5/5-1d, the Personal Information Form, which carries the Social Security numbers of both parents and any dependent children. Form 4-11 instructs you to file it with the petition.²
Form 4-17 or 4-17a, the Financial Disclosure Affidavit. Form 4-17 is the full version; 4-17a is a shorter alternative. Both are on nycourts.gov.⁴

What to Attach to the Financial Disclosure

The affidavit is not enough by itself. It expects supporting records:

Your most recently filed federal and state income tax returns, with all schedules.
The W-2s and 1099s that went with those returns. If you didn’t file for the most recent year, bring the W-2 from the last year you did.⁴
Your two most recent pay stubs.⁵
Proof of the expenses your petition rests on: rent, childcare invoices, medical bills, tuition statements. Bring these to the hearing even if you don’t attach them to the initial filing.

If you’re claiming a job loss, also pull together documentation of unemployment benefits and evidence of your job search. The court takes “diligent attempts to secure employment” seriously, and a record of applications strengthens the petition.

Filling Out Form 4-11

The form runs two pages and is mostly checkboxes, but the details matter.

At the top, you enter the court’s county, the docket number, and the file number from the existing support order. Those numbers appear in the upper right corner of your current order or the original judgment. Copy them exactly. Wrong numbers cause the clerk to reject the filing.

Next come the names and addresses of the petitioner (you) and the respondent (the other parent), followed by the children covered by the existing order.

Paragraph 6 is where you check your ground: substantial change of circumstances, three years elapsed, or 15 percent income change.² If you check the substantial-change box, describe what happened. Be specific: name the event, give the date, and say how it affects either parent’s ability to pay or the child’s needs. “I lost my job in March 2026 in a company-wide layoff” is far more useful than “my financial situation has changed.”

The form also asks for the date of the existing order and the current payment amount. Take both directly from the order. Don’t round.

Where and How to File

Bring the completed Form 4-11, the Personal Information Form, your Financial Disclosure Affidavit, and your supporting records to the Family Court clerk’s office. Some Family Courts also accept filings through the Electronic Document Delivery System (EDDS), which lets you upload documents online. Not every court and case type is eligible, so check the authorized courts and case types tool on the Unified Court System website before relying on it.⁶ An EDDS submission counts as filed only after the clerk sends a notice of acceptance. Uploading alone is not filing.

Once the clerk accepts your filing, the court issues a summons with a hearing date. That summons and a copy of the petition then have to reach the other parent.

Serving the Other Parent

You cannot hand the papers over yourself. New York law bars any party to the case from serving legal documents.⁷ Someone else has to deliver them: a friend, a relative, or a professional process server, at least 18 years old and not a party to the case.⁸

After service, that person fills out an Affidavit of Service and signs it in front of a notary. The affidavit records the date, time, and place of delivery and describes the person served.⁸ File the completed affidavit with the clerk. Without it, the court has no proof the respondent was notified and the case cannot move forward.

At the Hearing

A Support Magistrate, not a judge, runs the hearing. Both parents testify about income, expenses, and the cost of raising the child. You can present documents, call witnesses, and cross-examine the other parent and any witnesses they bring.¹

Bring originals, not just copies. The Magistrate may want to see original tax returns, pay stubs, and expense receipts. Also bring proof of any specific costs you want factored into the new number: childcare invoices, medical bills, tuition statements. Concrete records leave less room for the other side to dispute.

After hearing both sides, the Magistrate applies the Child Support Standards Act formula and issues a new order. Either party can file objections with a Family Court judge within 30 days if they think the Magistrate was wrong on the facts or the law.

File as Soon as You Can

This is the rule people underestimate. Under federal and New York law, the court cannot erase child support that has already come due. Every missed payment becomes a judgment the moment it is due, enforceable like any other court judgment, and it cannot be retroactively reduced or forgiven — not by a New York court, not by another state’s court, and not through bankruptcy.⁹

New York’s statute reinforces the point: a modification “shall not reduce or annul child support arrears accrued prior to the making of an application.”³ The takeaway is simple. If your income drops or your circumstances change, file immediately. A modification can only reach back to the date you filed the petition. Every week you wait, the old amount keeps accruing as legally enforceable debt.

When Form 4-11 Isn’t the Right Tool

A few situations call for something other than filing this petition.

If your support is paid through the Support Collection Unit (SCU), the order is automatically reviewed every three years for a possible adjustment, and either parent can request a review at any time without filing Form 4-11. Both parents get notice of any proposed change and can request a hearing before a Support Magistrate if they disagree.¹

Cost-of-Living Adjustments (COLA) are handled separately by the Office of Child Support Enforcement. A computerized system screens cases once the order is at least two years old or hasn’t been modified in the last two years, and eligible parents are notified.¹⁰ COLA only raises orders. For a reduction, you still need to file a modification petition.

If the other parent has moved out of New York, jurisdiction gets more complicated. Under the Uniform Interstate Family Support Act, New York keeps exclusive authority to modify its own order only if the order is the controlling order and at least one party or the child still lives in New York when the modification is filed. If everyone has left, New York loses modification authority, and the petition has to go to a state that has jurisdiction over one of the parties (or both parties consent in writing to another state taking over).¹¹

If any of this is more than you want to handle alone, New York’s Child Support Services program, run through local offices under the federal Title IV-D system, can help you file a modification petition. If your case is already in the IV-D system — typically because support is paid through the SCU — the agency can start the review process for you. Contact your local child support office or visit childsupport.ny.gov to open a case or request a review.

1
New York State Unified Court System. New York City Family Court Child and/or Spousal Support
2
New York State Unified Court System. Form 4-11 – Petition for Modification of an Order of Support
3
New York State Senate. New York Family Court Act Section 451
4
New York State Unified Court System. Financial Disclosure Affirmation
5
New York State Unified Court System. Financial Disclosure Affidavit (Short Form)
6
New York State Unified Court System. EDDS Home – Unified Court System
7
New York Courts. How Legal Papers Are Delivered (Service)
8
New York State Unified Court System. How to Serve Papers When Commencing an Action or Proceeding
9
Office of the Law Revision Counsel. 42 USC 666 – Requirement of Statutorily Prescribed Procedures
10
NYC.gov. Guide to Child Support Services
11
New York State Senate. New York Family Court Act Section 580-205