How to Establish Paternity in Wisconsin
Reviewed by DocDraft Legal Team · Wisconsin · Last updated 2026-09-12
In Wisconsin, establishing paternity means legally identifying a child's father so the child gains rights to support, inheritance, health coverage, and benefits and the father can seek legal custody and physical placement. Unmarried parents who agree can establish paternity without court by signing a Voluntary Paternity Acknowledgment, which once filed with the state Register of Vital Records has the same force and effect as a court judgment of paternity. When parents do not agree, a court determines paternity, often after genetic testing arranged through the Bureau of Child Support. Two Wisconsin rules are load-bearing. An action to establish paternity must be commenced within 19 years of the child's birth or it is barred (Wis. Stat. 893.88), one of the longest fixed limitation periods in the country. And genetic testing carries a defined threshold: if tests show the alleged father is not excluded and the statistical probability of parentage is 99.0 percent or higher, he is rebuttably presumed to be the child's parent (Wis. Stat. 767.84). A man married to the mother when the child is conceived or born is also presumed the father (Wis. Stat. 891.41). Attorney review of your situation is available through DocDraft.
Find out where you stand in Wisconsin
Where are you in establishing paternity?
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How long do I have to establish paternity in Wisconsin?
Under Wis. Stat. 893.88, an action to establish the paternity of a child must be commenced within 19 years of the date of the child's birth, or it is barred. That is one of the longest fixed limitation periods for a paternity action of any state.
What is the marital presumption of paternity in Wisconsin?
Under Wis. Stat. 891.41, a man is presumed the natural father if he and the mother are or have been married and the child is conceived or born after the marriage and before a decree of legal separation, annulment, or divorce between them.
What genetic-testing result establishes paternity in Wisconsin?
Under Wis. Stat. 767.84, if genetic tests show the alleged father is not excluded and the statistical probability of his parentage is 99.0 percent or higher, he is rebuttably presumed to be the child's parent. A 99.0 percent result can also support a conclusive administrative determination of paternity.
Can paternity be established years after a child's birth in Wisconsin?
Yes. Wisconsin allows an action to establish paternity to be commenced any time within 19 years of the child's birth (Wis. Stat. 893.88), one of the longest windows of any state. After 19 years the action is barred. This is far longer than the fixed limits most states set.
Wisconsin paternity law at a glance
Wisconsin gives parents an unusually long window to establish paternity: an action must be commenced within 19 years of the child's birth or it is barred (Wis. Stat. 893.88), among the longest in the country. Unmarried parents who agree can establish paternity without court by signing a Voluntary Paternity Acknowledgment, which once filed with the state Register of Vital Records has the effect of a court judgment. Genetic testing has a defined threshold. Under Wis. Stat. 767.84, if tests show the alleged father is not excluded and the statistical probability of parentage is 99.0 percent or higher, he is rebuttably presumed to be the child's parent. A man married to the mother when the child is conceived or born is presumed the father (Wis. Stat. 891.41). Signing an acknowledgment establishes legal fatherhood but does not by itself grant custody or physical placement, which a court decides separately.
Establishing Wisconsin paternity for a child of unmarried parents
Suppose a child is born in Wisconsin to unmarried parents who agree on the father. At the hospital both sign a Voluntary Paternity Acknowledgment, filed with the state Register of Vital Records, giving it the effect of a court judgment. If one parent has doubts, a signer can rescind within 60 days of filing, the federal window; after that, undoing the acknowledgment becomes significantly harder. Had the parents disputed paternity, either could ask the county child support agency to open a case or file in the circuit court within 19 years of the child's birth (Wis. Stat. 893.88). The court could order genetic testing, and a 99.0 percent result would rebuttably presume the man to be the parent (Wis. Stat. 767.84). Had the mother been married, the husband would be presumed the father under Wis. Stat. 891.41. Custody and physical placement are decided separately. Attorney review is available through DocDraft.
Relevant Laws
Wis. Stat. 893.88 (limitation on paternity actions)
Provides that, notwithstanding s. 990.06, an action for the establishment of the paternity of a child shall be commenced within 19 years of the date of the birth of the child or be barred.
Wis. Stat. 891.41 (presumption of paternity based on marriage)
Provides that a man is presumed to be the natural father of a child if he and the child's natural mother are or have been married to each other and the child is conceived or born after marriage and before the granting of a decree of legal separation, annulment, or divorce.
Wis. Stat. 767.84 (genetic-testing probability threshold)
Provides that if genetic tests show the alleged father is not excluded and the statistical probability of his parentage is 99.0 percent or higher, the alleged father is rebuttably presumed to be the child's parent.
Wis. Stat. 767.804 (conclusive determination of paternity)
Provides for a conclusive determination of paternity, including where genetic test results show a statistical probability of parentage of 99.0 percent or higher, giving paternity the effect of a judgment without a contested trial.
Wis. Stat. 767.805 (voluntary acknowledgment of paternity)
Provides that a statement acknowledging paternity filed with the state Register of Vital Records under s. 69.15 has the effect of a judgment of paternity, subject to the 60-day rescission period and later challenge for limited cause.
Wisconsin Bureau of Child Support
The Bureau of Child Support and county child support agencies help parents establish paternity, arrange genetic testing, and establish and enforce child support once paternity is established.
Regional Variances
Wisconsin paternity rules at a glance
Voluntary path and form
Unmarried parents establish paternity by signing a Voluntary Paternity Acknowledgment, filed with the state Register of Vital Records, which has the same force and effect as a court judgment of paternity (Wis. Stat. 767.805).
Rescission window
A signer may rescind within 60 days of filing, the federal window. After that, challenging the acknowledgment becomes significantly more difficult and is limited to grounds such as fraud, duress, or material mistake.
Deadline to establish
An action to establish paternity must be commenced within 19 years of the child's birth or it is barred (Wis. Stat. 893.88), among the longest fixed limitation periods in the country.
Marital presumption
A man is presumed the natural father if he and the mother are or have been married and the child is conceived or born after marriage and before a decree of legal separation, annulment, or divorce (Wis. Stat. 891.41).
Genetic-testing threshold
If tests show the alleged father is not excluded and the statistical probability of parentage is 99.0 percent or higher, he is rebuttably presumed to be the parent, and that result can support a conclusive determination (Wis. Stat. 767.84, 767.804).
Custody handled separately
Establishing paternity confers legal fatherhood and the duty of support, but legal custody and physical placement are decided separately by the circuit court based on the child's best interests.
Suggested Compliance Checklist
Confirm whether the mother was married
Before signing or filing anything days after startingDetermine whether the man and mother are or have been married with the child conceived or born after marriage and before a decree of legal separation, annulment, or divorce, which makes him the presumed father (Wis. Stat. 891.41).
Arrange genetic testing if paternity is uncertain
Before signing an acknowledgment days after startingIf there is doubt, obtain genetic testing through the child support agency or the court. Under Wis. Stat. 767.84, a result showing the alleged father is not excluded with a probability of 99.0 percent or higher rebuttably presumes him to be the parent.
Sign and file the Voluntary Paternity Acknowledgment
At the hospital or through the child support agency days after startingUnmarried parents who agree sign the Voluntary Paternity Acknowledgment and file it with the state Register of Vital Records, which gives it the force of a court judgment (Wis. Stat. 767.805). Keep a copy. Attorney review of your paternity matter is available through DocDraft.
Track the 60-day rescission window
Within 60 days of filing days after startingIf you need to cancel a signed acknowledgment, rescind within 60 days of filing, the federal window. After that, challenging the acknowledgment becomes significantly more difficult and is limited to fraud, duress, or material mistake of fact.
File within 19 years if paternity is disputed
Within 19 years of the child's birth days after startingIf parents do not agree, ask the county child support agency to start a case or file a paternity action in the circuit court, which must be commenced within 19 years of the child's birth (Wis. Stat. 893.88). The court can order genetic testing and enter a judgment.
Handle custody and placement separately
After paternity is established days after startingEstablishing paternity does not by itself grant custody or physical placement. Ask the circuit court to decide legal custody and physical placement based on the child's best interests, and keep the acknowledgment, testing, and orders on file.
| Task | Description | Document | Days after starting |
|---|---|---|---|
| Confirm whether the mother was married | Determine whether the man and mother are or have been married with the child conceived or born after marriage and before a decree of legal separation, annulment, or divorce, which makes him the presumed father (Wis. Stat. 891.41). | - | Before signing or filing anything |
| Arrange genetic testing if paternity is uncertain | If there is doubt, obtain genetic testing through the child support agency or the court. Under Wis. Stat. 767.84, a result showing the alleged father is not excluded with a probability of 99.0 percent or higher rebuttably presumes him to be the parent. | - | Before signing an acknowledgment |
| Sign and file the Voluntary Paternity Acknowledgment | Unmarried parents who agree sign the Voluntary Paternity Acknowledgment and file it with the state Register of Vital Records, which gives it the force of a court judgment (Wis. Stat. 767.805). Keep a copy. Attorney review of your paternity matter is available through DocDraft. | - | At the hospital or through the child support agency |
| Track the 60-day rescission window | If you need to cancel a signed acknowledgment, rescind within 60 days of filing, the federal window. After that, challenging the acknowledgment becomes significantly more difficult and is limited to fraud, duress, or material mistake of fact. | - | Within 60 days of filing |
| File within 19 years if paternity is disputed | If parents do not agree, ask the county child support agency to start a case or file a paternity action in the circuit court, which must be commenced within 19 years of the child's birth (Wis. Stat. 893.88). The court can order genetic testing and enter a judgment. | - | Within 19 years of the child's birth |
| Handle custody and placement separately | Establishing paternity does not by itself grant custody or physical placement. Ask the circuit court to decide legal custody and physical placement based on the child's best interests, and keep the acknowledgment, testing, and orders on file. | - | After paternity is established |
Frequently Asked Questions
Establishing paternity in Wisconsin means legally identifying a child's father so the child can receive support, inheritance, health coverage, and benefits, and the father can seek legal custody and physical placement. It can be done by signing a Voluntary Paternity Acknowledgment or through a court action (Wis. Stat. 767.84, 893.88).
Unmarried parents who agree sign a Voluntary Paternity Acknowledgment and file it with the state Register of Vital Records, which gives it the force and effect of a court judgment. If parents disagree, the circuit court determines paternity, often after ordering genetic testing (Wis. Stat. 767.84).
It is a form unmarried parents sign to establish legal fatherhood without going to court. Once filed with the state Register of Vital Records, it has the same force and effect as a court judgment of paternity, though it does not by itself grant custody or physical placement.
Yes. Under Wis. Stat. 893.88, an action to establish the paternity of a child must be commenced within 19 years of the date of the child's birth, or it is barred. There is also a 60-day window to rescind a signed Voluntary Paternity Acknowledgment.
Yes, within a limited window. A signer may rescind a Voluntary Paternity Acknowledgment within 60 days of filing, the federal rescission window. After that period, challenging the acknowledgment becomes significantly more difficult and is generally limited to fraud, duress, or material mistake of fact.
Not by itself. Signing a Voluntary Paternity Acknowledgment or obtaining a paternity judgment establishes legal fatherhood and the duty of support, but legal custody and physical placement are decided separately by the circuit court based on the child's best interests.
Under Wis. Stat. 767.84, if genetic tests show the alleged father is not excluded and the statistical probability of his parentage is 99.0 percent or higher, he is rebuttably presumed to be the child's parent. A 99.0 percent result can also support a conclusive administrative determination of paternity.
The Bureau of Child Support and county child support agencies help establish paternity and arrange genetic testing, and the Voluntary Paternity Acknowledgment is filed with the state Register of Vital Records. When paternity is contested, the circuit court determines it and can order genetic testing.
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