Wis. Stat. § 48.81: Who may be adopted.

Any child who is present in this state at the time the petition for adoption is filed may be adopted if any of the following criteria are met:

(1) Both of the child’s parents are deceased.

(2) The parental rights of both of the child’s parents with respect to the child have been terminated under subch. VIII or in another state or a foreign jurisdiction.

(3) The parental rights of one of the child’s parents with respect to the child have been terminated under subch. VIII or in another state or a foreign jurisdiction and the child’s other parent is deceased.

(4) The person filing the petition for adoption is the spouse of the child’s parent with whom the child and the child’s parent reside and either of the following applies:

(a) The child’s other parent is deceased.

(b) The parental rights of the child’s other parent with respect to the child have been terminated under subch. VIII or in another state or a foreign jurisdiction.

(5) Section 48.839 (3) (b) applies.

(6) The child is being adopted under s. 48.97 (3).