How to Modify Child Support in Wisconsin
Reviewed by DocDraft Legal Team · Wisconsin · Last updated September 21, 2026
In Wisconsin, a child support modification is a court order that changes the amount of an existing child support order after circumstances change, and Wisconsin is distinctive in presuming a substantial change once 33 months have passed since the last order (Wis. Stat. 767.59(1f)(b)2). A circuit court may revise the amount only upon a finding of a substantial change in circumstances (Wis. Stat. 767.59(1f)). The statute treats the 33-month gap as a rebuttable presumption of a substantial change, unless your order is already set as a percentage of parental income, and a change in the payer's income can also count (Wis. Stat. 767.59(1f)(c)). Wisconsin sets support using a percentage-of-income guideline, so a real income change up or down can make the current amount too high or too low. You can ask for a change in two ways. You can file a Notice of Motion and Motion to Change (Form FA-4170V) with the circuit court that issued your order, or ask your county child support agency, overseen by the Department of Children and Families, for a free review. A revision applies only from the date the other parent receives notice, so support that already came due cannot be reduced (Wis. Stat. 767.59(1m)). Keep paying your current order until the court changes it. Attorney review of your filing is available through DocDraft.
Find out where you stand in Wisconsin
Where are you with changing your child support order?
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How do I modify child support in Wisconsin?
File a Notice of Motion and Motion to Change (Form FA-4170V) with the circuit court that issued your order, or ask your county child support agency for a free review. A court may revise support only on a finding of a substantial change in circumstances (Wis. Stat. 767.59(1f)).
How much does income have to change to modify child support in Wisconsin?
Wisconsin sets no fixed statutory percentage for a court request; you must show a substantial change in circumstances (Wis. Stat. 767.59(1f)). One presumption is that 33 months have passed since the last order. For an agency review, a raise or drop changing support by more than 50 dollars a month can qualify.
How far back can a child support change go in Wisconsin?
A revision applies only from the date the other parent receives notice of your action; a court cannot reduce support or arrears that came due before that notice, except to correct calculation errors (Wis. Stat. 767.59(1m)). Filing promptly protects you, and keep paying the current order until it is changed.
Which court handles child support modifications in Wisconsin?
The circuit court in the county where your existing order was entered handles modifications through its family court. If your county child support agency manages your case, you can also ask it for a free review; the agency can take the matter to the circuit court when a change is warranted.
Wisconsin child support modification at a glance
In Wisconsin, a child support modification is a circuit court changing the amount of an existing support order after circumstances change, and the court may act only on a finding of a substantial change in circumstances (Wis. Stat. 767.59(1f)). Wisconsin presumes a substantial change once 33 months have passed since the last order, unless the order is set as a percentage of income, and a change in the payer's income can also count. You file a Notice of Motion and Motion to Change (Form FA-4170V) with the circuit court, or ask your county child support agency, overseen by the Department of Children and Families, for a free review. A revision applies only from the date the other parent receives notice, so support that already came due cannot be reduced (Wis. Stat. 767.59(1m)).
Modifying a Wisconsin order after 33 months
Suppose your Wisconsin order was entered 34 months ago, and because more than 33 months have passed you have a presumed substantial change in circumstances (Wis. Stat. 767.59(1f)(b)2). You complete a Notice of Motion and Motion to Change (Form FA-4170V), attach current income proof, and file it with the circuit court that issued your order. You serve the other parent, which gives notice and sets the earliest date any change can apply (Wis. Stat. 767.59(1m)). You keep paying the current amount until the court rules. At the hearing the court applies the percentage-of-income guideline and signs a new order effective from the date of notice. Attorney review of your filing is available through DocDraft.
Relevant Laws
Wis. Stat. 767.59(1f) (revision on a substantial change in circumstances)
Provides that a revision of the amount of child support may be made only upon a finding of a substantial change in circumstances, and makes the expiration of 33 months after the last child support order a rebuttable presumption of a substantial change unless the order is expressed as a percentage of parental income.
Wis. Stat. 767.59(1m) (revisions are prospective from notice)
Provides that the court may not revise the amount of child support due, or arrearages that have accrued, prior to the date that notice of the action is given to the respondent, except to correct previous errors in calculations, so a change cannot reach support that already came due.
Wisconsin DCF: Reviewing a Court Order for a Change
The Department of Children and Families explains that a parent may request a free review of a child support case from the local county child support agency, that an order may be reviewed after three years, and that an income change moving the order by more than 50 dollars a month can support a change.
Wisconsin Court System Form FA-4170V
The Notice of Motion and Motion to Change: Legal Custody, Physical Placement, Child Support, Maintenance or Arrears Payment is the statewide court form used to give notice and ask the circuit court to change a current child support order. It is provided free in English and Spanish.
Regional Variances
Wisconsin child support modification rules at a glance
Qualifying threshold
A revision requires a finding of a substantial change in circumstances (Wis. Stat. 767.59(1f)). Wisconsin presumes a substantial change once 33 months have passed since the last order, unless the order is set as a percentage of income, and a change in the payer's income can also count.
Where to file
The circuit court in the county where your existing order was entered, through its family court. If your county child support agency, overseen by the Department of Children and Families, manages your case, you can also ask it for a free review.
Modification form
Form FA-4170V, the Notice of Motion and Motion to Change: Legal Custody, Physical Placement, Child Support, Maintenance or Arrears Payment, filed with a current financial disclosure. The Wisconsin Court System provides it free in English and Spanish.
Retroactivity
A revision applies only from the date the other parent receives notice of the action; support and arrears that came due before that notice cannot be reduced, except to correct calculation errors (Wis. Stat. 767.59(1m)).
Periodic review
If your county child support agency handles your case, you can generally request a review about every three years without showing a change, under federal rules, and sooner when a substantial change occurs.
Suggested Compliance Checklist
Gather proof of your changed circumstances
Before you file days after startingCollect current pay stubs, tax returns, and proof of the change (job loss, income change, or a new placement schedule), and note whether 33 months have passed since your last order (Wis. Stat. 767.59(1f)). Attorney review of your filing is available through DocDraft.
Complete the Motion to Change (Form FA-4170V)
As soon as your circumstances change days after startingFill out Form FA-4170V asking to change child support, describe the changed circumstances, and attach a current financial disclosure of your income. Use the free Wisconsin Court System forms and instructions.
File with the circuit court
Promptly (a change reaches back only to notice) days after startingFile your motion with the clerk of the circuit court that issued your order and pay the fee, or ask about a fee waiver. Because a revision reaches back only to notice, file promptly (Wis. Stat. 767.59(1m)).
Serve the other parent
As the court directs before the hearing days after startingServe the other parent with your filed motion as the court directs, then file proof of service. Notice is required for the hearing and sets the earliest date your revision can take effect (Wis. Stat. 767.59(1m)).
Consider a free agency review
Anytime your case is with the agency days after startingIf your county child support agency manages your case, ask it for a free review. The agency generally acts when an income change would move the order by more than 50 dollars a month, or after three years.
Attend the hearing and get the new order
On your hearing date days after startingGo to the hearing with your income proof, let the court apply Wisconsin's percentage-of-income guideline, and get the signed order effective back to the date of notice. Keep paying the current order until then.
| Task | Description | Document | Days after starting |
|---|---|---|---|
| Gather proof of your changed circumstances | Collect current pay stubs, tax returns, and proof of the change (job loss, income change, or a new placement schedule), and note whether 33 months have passed since your last order (Wis. Stat. 767.59(1f)). Attorney review of your filing is available through DocDraft. | - | Before you file |
| Complete the Motion to Change (Form FA-4170V) | Fill out Form FA-4170V asking to change child support, describe the changed circumstances, and attach a current financial disclosure of your income. Use the free Wisconsin Court System forms and instructions. | - | As soon as your circumstances change |
| File with the circuit court | File your motion with the clerk of the circuit court that issued your order and pay the fee, or ask about a fee waiver. Because a revision reaches back only to notice, file promptly (Wis. Stat. 767.59(1m)). | - | Promptly (a change reaches back only to notice) |
| Serve the other parent | Serve the other parent with your filed motion as the court directs, then file proof of service. Notice is required for the hearing and sets the earliest date your revision can take effect (Wis. Stat. 767.59(1m)). | - | As the court directs before the hearing |
| Consider a free agency review | If your county child support agency manages your case, ask it for a free review. The agency generally acts when an income change would move the order by more than 50 dollars a month, or after three years. | - | Anytime your case is with the agency |
| Attend the hearing and get the new order | Go to the hearing with your income proof, let the court apply Wisconsin's percentage-of-income guideline, and get the signed order effective back to the date of notice. Keep paying the current order until then. | - | On your hearing date |
Frequently Asked Questions
A real, involuntary income drop can be a substantial change in circumstances, but you must file a motion to change the amount; support keeps accruing at the old rate until the court acts (Wis. Stat. 767.59(1m)). A court may consider your earning capacity. Do not simply stop paying.
No. After 33 months since the last order, Wisconsin presumes a substantial change in circumstances, but the presumption is rebuttable and the amount still follows the guideline (Wis. Stat. 767.59(1f)(b)2). If your order is set as a percentage of income, the 33-month presumption does not apply.
No. Either parent can file a Notice of Motion and Motion to Change on their own, and the other parent is served and can respond. If both agree on a new amount, they can submit a written stipulation for the court to approve, and the court still checks it against the guideline.
After you file Form FA-4170V, the circuit court sets a hearing, often several weeks to a few months out depending on the county. An uncontested change or a county agency review can be faster. Because a change reaches back only to notice, filing promptly protects you (Wis. Stat. 767.59(1m)).
Yes. If your county child support agency, overseen by the Department of Children and Families, manages your case, you can ask it for a free review. The agency generally acts when an income change would move the order by more than 50 dollars a month, and can take the matter to court.
You can request a change whenever a substantial change in circumstances occurs. If your county child support agency handles your case, you can generally ask for a review every three years even without a change, under federal rules, and sooner when a substantial change happens.
A revision changes support only from the date the other parent receives notice; support and arrears that came due before that notice cannot be reduced, except to correct calculation errors (Wis. Stat. 767.59(1m)). Keep paying your current order to avoid building arrears while your motion is pending.
You file Form FA-4170V, the Notice of Motion and Motion to Change, with the circuit court, and attach a current financial disclosure showing your income. The Wisconsin Court System provides the form and instructions at no charge in English and Spanish on its website.
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