Determination of paternity – the identity of a child’s father – is governed in Wisconsin by Wis. Stat. Secs. 767.80 - 767.895. The sections below discuss some of the more common issues that can arise regarding determinations of paternity. As discussed below, in some cases one man is the child’s biological father and another man is the child’s legal father.

Paternity Acknowledgment

Outside of marriage, the identity of a child’s father is usually established in Wisconsin by voluntary acknowledgment of paternity pursuant to Wis. Stats. Sec. 767.805. A voluntary acknowledgment of paternity is used to establish who the father is on a birth certificate, and is usually signed shortly after the child’s birth, often while the parties are still in the hospital. Use caution in signing a voluntary acknowledgment of paternity; do not agree to sign if you have any doubt regarding who the biological father is. You may rescind or withdraw from a voluntary acknowledgment of paternity within 60 days of signing; after that, it is extremely difficult to change parental responsibility for a child. Wis. Stats. Sec. 69.15(3m). A court may void a determination of paternity if fraud, duress, or mistake of fact is shown. Wis. Stats. Sec. 767.805(5).

Paternity Action

Alternatively, a parent may establish paternity by filing a paternity action in court. A paternity case may be brought at any time, including during the pregnancy. When a paternity case is initiated, either party may request genetic testing to determine if the alleged father is in fact the biological father. Genetic testing may exclude a man as the father, or establish that there is an extremely high likelihood (but not an absolute certainty) that a man is the father.

Marital Presumption

A child born during a marriage, or born before a marriage to two people who subsequently marry, is presumed to be the husband’s child. Wis. Stats. Sec. 891.41. Either party, or a third party, may contest paternity and try to defeat the presumption of paternity through genetic testing. Wis. Stats. Sec. 891.41(2). Sometimes a husband may assert parental rights to a child even if genetic testing reveals a different biological father. See, for example, the Wisconsin Supreme Court case of Randy A.J. v. Norma I.J.

Custody, Placement, and Child Support

Once paternity is established, issues of custody, placement, and child support are generally treated the same as in a divorce. Please refer to those sections of this Website. There is, however, a debate in Wisconsin regarding whether the move-away statute (Wis. Stat. Sec. 767.481) applies to paternity cases; some judges apply this statute to paternity cases, and others do not.

Name Change

If both parents agree, the Paternity Judgment can include a change in the child’s first and/or last name. If only one parent wants to change the child’s last name, the court has authority to change the child’s last name to a hyphenated name containing both parents’ last names, if the court finds that to be in the best interest of the child. Wis. Stats. Sec. 767.89(3m).