767.80.Determination of paternity.
Subch. IX: Paternity · Last amended 2019 · Current through 2025 Wisconsin Act 247 · Last verified September 8, 2026
Full Text of Section 767.80
Official Notes
Wisconsin prints certain labelled notes with the statute — effective-date notes, cross-references, and notes of the Judicial Council. They are reproduced verbatim below. The unlabelled digest of court decisions that the Legislative Reference Bureau prints after them is annotation rather than statute, and is not reproduced.
Cross-reference: See also ch. DCF 151, Wis. adm. code.
Amendment History
Wisconsin prints each section’s legislative history as a single “History” line naming every act that created or amended it, and every renumbering. It is reproduced verbatim below.
History: 1979 c. 352; 1981 c. 20 s. 2202 (20) (m); 1983 a. 447; 1985 a. 29; 1987 a. 27, 355, 399, 413; 1989 a. 31, 212; 1993 a. 326, 481; 1995 a. 27 s. 9126 (19); 1995 a. 68, 100, 201, 275, 404; 1997 a. 191; 1999 a. 9; 2001 a. 61; 2005 a. 443 ss. 12, 184, 241; Stats. 2005 s. 767.80; 2007 a. 97; 2009 a. 321; 2015 a. 82 s. 12; 2017 a. 334; 2019 a. 95.
Plain-English Summary
The opening section of the paternity subchapter, and the widest door in the chapter.
Who may sue. The child; the child's natural mother; a male presumed to be the father, unless paternity has already been settled by genetic test or acknowledgment; a male alleged or alleging himself to be the father; the personal representative of any of those if they have died; the child's legal or physical custodian; the state, in the circumstances the chapter specifies and through the attorney it designates; a guardian ad litem appointed for the child; a parent of the mother or of an alleged father who is or may be liable to maintain a dependent person's child; and, alongside a petition for visitation, a parent of someone who filed a declaration of paternal interest or an early statement acknowledging paternity. The action may also be for a declaratory judgment, and may be brought to rebut a presumption of paternity as well as to establish one.
Where. In the county where the child or the alleged father lives or is found, or, if the father has died, where his estate is or could be probated.
What cannot stop it. An agreement between an alleged or presumed father and the mother or child does not bar the action, whatever its terms — unless the court approved it, and the court may approve a waiver only after determining it is in the child's best interest. Nobody may waive the use of this procedure. If the action is started before the birth, everything is stayed until afterwards except service, pleadings, the first appearance, and depositions to preserve testimony.
The petition. Titled “In re the paternity of A.B.”, it names the child and date of birth or states that the mother is pregnant, names any alleged father — defined to include any male who had intercourse with the mother during a possible time of conception — and discloses any other paternity proceeding anywhere. It must give notice of the right to request a genetic test.
The state's duty. Where a birth record names no father and paternity has not otherwise been settled, the designated attorney must commence an action within 6 months of being notified. Matters referred from children's court get priority, and the attorney must report back to the referring court within 30 days on whether an action has been or will be brought. That attorney cannot at the same time act as the child's guardian ad litem.
Finally, the clerk gives every petitioner but the state, free of charge, a document setting out the support percentage standard and the deviation factors.
Frequently Asked Questions
Who can file a paternity case in Wisconsin?
The child, the mother, a presumed father, a man alleged or alleging himself to be the father, a deceased party's personal representative, the child's legal or physical custodian, the state, a guardian ad litem for the child, and in defined circumstances a parent of one of those people.
Can we agree not to bring a paternity case?
Not effectively, unless the court approves the agreement — and the court must first determine that the waiver is in the child's best interest, and may not approve one that is contrary to it.
Can a paternity case be started before the baby is born?
Yes, but proceedings are stayed until after the birth, except service of process, service and filing of pleadings, the first appearance, and depositions to preserve testimony.
When must the state bring a paternity action?
Within 6 months after being notified that no father is named on the birth record of a child residing in the county, where paternity has not been conclusively determined, acknowledged or adjudicated.
Where is a Wisconsin paternity case filed?
In the county where the child or the alleged father resides or is found, or, if the father has died, where his estate has been or could be probated.