Wis. Stat. § 767.521: Action by state for child support.

The state or its delegate under s. 49.22 (7) shall bring an action for support of a minor child under s. 767.001 (1) (f) or for paternity determination and child support under s. 767.80 if the child’s right to support is assigned to the state under s. 48.57 (3m) (b) 2. or (3n) (b) 2., 48.645 (3), 49.145 (2) (s), 49.19 (4) (h) 1. b., or 49.775 (2) (bm) and all of the following apply:

(1) The child has been deprived of parental support by reason of the continued absence of a parent from the home.

(2) A court has not issued an order under s. 767.511 requiring the parent who is absent from the home to support the child.