Back child support in Wisconsin is unpaid, court-ordered support that has accrued under a valid order, and it carries serious consequences. As of March 2026, past-due support accrues simple interest at 0.5% per month (6% annually), and arrears cannot be retroactively reduced or erased except for genuine calculation errors. The state enforces collection through wage withholding, tax intercepts, liens, license suspension, and contempt of court — with no statute of limitations on collecting arrears.
This guide explains how back child support works in Wisconsin, how interest is calculated, what enforcement tools the state uses, and what options exist for a parent who owes child support debt. Whether you are owed past due child support or you owe child support arrears, understanding Wis. Stat. § 767.511 and Chapter 767 will help you protect your rights.
This article is general legal information, not legal advice. Consult a licensed Wisconsin family law attorney for guidance on your specific situation.
Key Facts: Back Child Support in Wisconsin
| Topic | Wisconsin Rule |
|---|---|
| Interest on arrears | 0.5% per month (6% annually) since April 1, 2014 |
| Statutory interest text | 1% per month under Wis. Stat. § 767.511(6m); 0.5% applied administratively |
| Retroactive modification | Prohibited — prospective only from date of service (§ 767.59(1m)) |
| Statute of limitations | None on enforcement; arrears collectible indefinitely |
| Automatic lien threshold | $500 or more in past-due support |
| License suspension trigger | 90+ days past due, with ability to pay (§ 767.73) |
| Passport denial threshold | $2,500 in arrears (federal program) |
| Tax intercept threshold | $500 (non-TANF) or $150 (TANF cases) |
| Statewide system | KIDS (Kids Information Data System) |
| Annual R&D fee | $35 (receiving parent) / $65 per court case |
As of March 2026. Verify all fees and thresholds with your local county child support agency or Clerk of Circuit Court.
What Is Back Child Support in Wisconsin?
Back child support in Wisconsin is unpaid support that accrues after a valid court order is in place — legally distinct from "retroactive" or past support ordered for a period before any order existed. Once support is ordered, every missed or partial payment becomes child support arrears tracked in the statewide KIDS system, and those arrears remain enforceable indefinitely with no statute of limitations.
Wisconsin courts and child support agencies treat two concepts differently. Child support arrears are unpaid amounts that accumulate after a valid support order under Wis. Stat. § 767.511. Retroactive or back support is support ordered for a time before any order existed, most common in paternity cases, where liability for past support reaches back only to the child's birth. Arrears are strictly enforceable once they accrue, while retroactive support is subject to judicial discretion. Understanding which category your child support debt falls into determines what defenses and credits may apply.
How Much Interest Accrues on Back Child Support in Wisconsin?
Back child support in Wisconsin accrues simple interest at 0.5% per month (6% annually) on any amount in arrears equal to or greater than one month of support. This administrative rate took effect April 1, 2014, lowering the prior rate of 1% per month (12% annually). Interest is mandatory — courts have no discretion to waive it, even when waiving would be equitable.
There is an important discrepancy between the statute and practice. The statutory text of Wis. Stat. § 767.511(6m) still references simple interest at 1 percent per month. However, the Wisconsin Department of Children and Families (DCF) has applied 0.5% per month (6% per year) since April 1, 2014. Interest charges begin when past-due support equals or exceeds one month's ordered amount, and interest accrues even while a parent is actively paying down the debt. Notably, interest is not charged on unpaid birth costs, fees, or medical support. The Wisconsin Court of Appeals confirmed in Douglas County Child Support Enforcement Unit v. Fisher that interest under subsection (6) is mandatory and the trial court has no discretion to deny it.
Can Back Child Support Be Reduced or Erased in Wisconsin?
No — back child support arrears in Wisconsin cannot be retroactively reduced or erased. Under Wis. Stat. § 767.59(1m), titled "Payment revisions prospective," a court may not revise the amount of support or arrears that accrued before the date the other party is served with the modification action, except to correct calculation errors. Modifications apply only going forward.
This prohibition stems from federal law. In 1986, Congress threatened Wisconsin with the loss of federal AFDC funds unless it banned retroactive modification, codified at 42 U.S.C. § 666(a)(9)(C). Wisconsin complied by enacting the predecessor to § 767.59(1m) in 1987. A 2021 published Court of Appeals decision (2020AP919) reaffirmed that a payment modification order is prospective only, overruling older cases that permitted retroactive reductions. The court held that delay in filing a motion — even a two-year delay — does not constitute a "calculation error" that would authorize reducing arrears. To stop arrears from growing, a parent who cannot afford payments must file for modification immediately, because relief begins only on the date of service.
What Are the Narrow Exceptions for Modifying Arrears?
Wisconsin allows only three narrow paths to adjust accrued back child support: correction of calculation errors, limited payer credits, and contempt-based remedies. Under Wis. Stat. § 767.59(1m), the court may revise arrears only "to correct previous errors in calculations" — a strict standard that does not include changed financial circumstances or delay in filing.
The first exception covers genuine arithmetic mistakes. In the Poehnelt case, a payer received a $2,800 credit for an overpayment caused by an error about the children's birthdates in the divorce complaint. The second exception, under § 767.59(1r), permits limited credit to a payer for certain payments made before the modification petition was served — but courts read this narrowly, and direct payments made outside the proper channels often do not qualify. The third pathway involves contempt of court. In the Frisch line of cases, where a payer concealed income, the court used its contempt powers to order a $100,000 purge payment to compensate the payee, a remedy the Wisconsin Supreme Court affirmed. These exceptions are fact-specific and require careful documentation, so a Wisconsin attorney should evaluate whether any applies to your child support debt.
How Does Wisconsin Enforce Back Child Support?
Wisconsin enforces back child support through a layered system of automatic and case-by-case tools administered by county child support agencies and the statewide KIDS system. Automatic enforcement includes interest charges, tax refund intercepts, and liens at $500 in arrears. Case-by-case actions include license suspension, contempt proceedings, and criminal nonsupport charges for chronic nonpayment.
The primary enforcement methods authorized under Chapter 767 include the following:
- Income (wage) withholding: The standard collection method; withholding may increase up to 50% above current support to pay down arrears, subject to federal Consumer Credit Protection Act limits.
- Property liens: Under Wisconsin law, a lien automatically attaches to real estate and vehicles when past-due support reaches $500 or more, without a court hearing.
- Tax refund intercepts: Federal and state refunds are seized at $500 in arrears (non-public-assistance cases) or $150 (TANF cases).
- License suspension: Under § 767.73, if support is 90+ days past due and the payer can pay, the court may suspend driving privileges for up to 2 years.
- Passport denial: Arrears exceeding $2,500 trigger federal passport denial.
- Contempt and criminal charges: Under § 767.78, agencies or parents may file for contempt.
Most cases begin with administrative tools before escalating to court action.
What Happens With Tax Refund Intercepts and Passport Denial?
Wisconsin intercepts federal and state tax refunds at low arrears thresholds, while the federal passport denial program requires $2,500 in past-due support. Tax intercept applies when a parent owes at least $500 in non-public-assistance cases or $150 in TANF cases. The intercepted refund flows to the Child Support Trust Fund and applies to back child support, interest, medical support, and birth costs.
For tax intercepts, Wisconsin mails a one-time notice the first year it reports the debt to the IRS or Department of Revenue, and the notice explains the appeal process. A tax-intercept fee of 10% per collection (capped at $25) is deducted before any remainder is returned. If a parent files a joint return, the spouse may recover their share by filing an IRS "Injured Spouse Allocation," though this does not stop collection from the obligor's portion. The federal passport program, originally enacted under the 1996 PRWORA and lowered to a $2,500 threshold by the 2005 Deficit Reduction Act, places obligors in the Consular Lookout Support System and holds passport applications for 90 days. As of May 9, 2026, the federal government expanded enforcement from blocking renewals to actively revoking valid passports, beginning with those owing $100,000 or more. Paying below $2,500 does not automatically remove a parent — only the submitting state can request withdrawal.
Can You Lose Your Driver's License for Back Child Support in Wisconsin?
Yes — Wisconsin can suspend your driver's license for unpaid child support. Under Wis. Stat. § 767.73, titled "Delinquent child or family support; suspension of operating privilege," if a parent fails to pay support that is 90 or more days past due and the court finds the parent has the ability to pay, the court may suspend operating privileges until all arrears are paid or satisfactory payment arrangements are made, up to a maximum of 2 years.
The license suspension framework originated in 1997 Wisconsin legislation that authorized suspension of licenses, permits, and other credentials for failure to pay child support. The key safeguard is the "ability to pay" finding — a court cannot suspend a license simply because arrears exist; it must determine the parent has the financial capacity to pay and has chosen not to. License suspension is one of the case-by-case enforcement tools, meaning it requires a court action rather than automatic administrative processing. A parent facing suspension can often avoid it by entering an acceptable payment plan. Because the suspension threatens a parent's ability to work and earn income to pay support, courts and agencies frequently use the threat of suspension as leverage to secure a payment agreement rather than imposing it outright.
What Are the Criminal Penalties for Not Paying Child Support in Wisconsin?
Wisconsin imposes both civil contempt and criminal nonsupport penalties for failing to pay child support. Civil contempt can result in fines up to $500 and up to 30 days in jail per violation. Criminal nonsupport for 120 or more consecutive days of missed support is a misdemeanor punishable by up to 9 months in jail and a $10,000 fine, escalating to a felony with up to 5 years in prison when arrears exceed $10,000.
Contempt proceedings under Wis. Stat. § 767.78 operate through Chapter 785, the general contempt statute. In counties where the State is an interested party, the county child support agency typically files an order to show cause and motion for contempt, and the court sets a hearing where the payer must explain the nonpayment. The judge then makes a finding and orders a payment arrangement, often with a "purge" condition the payer must satisfy to avoid jail. Criminal nonsupport under Wisconsin law is a separate, more serious track reserved for parents who deliberately and persistently refuse to support their children. These criminal penalties are not automatic — they require prosecution and a finding that the parent had the ability to pay. A parent facing either civil or criminal proceedings should consult a Wisconsin attorney immediately, because demonstrating inability to pay is a recognized defense.
What Are Your Options If You Owe Back Child Support in Wisconsin?
A parent who owes back child support in Wisconsin has several constructive options: negotiate a payment plan with the county child support agency, file for prospective modification of current support, and document all payments through proper channels. While arrears cannot be erased, proactive steps can stop license suspension, avoid contempt, and prevent the debt from compounding faster.
The most important action is filing for modification under Wis. Stat. § 767.59 the moment your income drops, because relief is prospective only from the date of service — every day of delay adds to nonmodifiable arrears at 6% annual interest. Second, work with your county child support agency to establish a realistic payment arrangement; agencies prefer steady payment over enforcement litigation, and a satisfactory arrangement can lift a license suspension. Third, always pay through the KIDS system and the Support Collections Trust Fund rather than directly to the other parent — direct payments may not be credited and rarely qualify for payer credit under § 767.59(1r). Fourth, keep meticulous records of every payment and expense. Finally, if you believe arrears were miscalculated, raise the calculation-error exception promptly, since that is one of the only paths to adjusting accrued back child support. An attorney can identify which strategies fit your circumstances.
How Do You Collect Past Due Child Support You Are Owed in Wisconsin?
A parent owed past due child support in Wisconsin can apply for free or low-cost enforcement services through their county child support agency, which then uses the full range of state tools to collect. Applying triggers automatic enforcement such as wage withholding, tax intercepts, and liens, and allows the agency to file contempt actions on your behalf. A $25 fee applies only for locate-only services.
To begin collection, file an application for child support services with your local county child support agency, or you receive services automatically if your family gets certain public assistance (these are "IV-D" public cases). Once enrolled, the agency enters and monitors the debt in the KIDS system, which automatically cross-checks Department of Transportation, Department of Natural Resources, and national new-hire databases to locate income and assets. The agency can initiate income withholding, intercept tax refunds, place liens, pursue license suspension, and file an order to show cause for contempt. Be aware of statutory fees: an annual $35 receiving-and-disbursing fee for the receiving parent (after $550 in support is received), a $65 per-case fee, and a 10% tax-intercept fee capped at $25. There is no statute of limitations on collecting Wisconsin arrears, so even debt owed for an adult child remains enforceable. For complex collection — especially across state lines — a Wisconsin family law attorney can supplement agency efforts.