Wis. Stat. § 632.857

If an insurer restricts or terminates an insured’s coverage for the treatment of a condition or complaint and, as a result, the insured becomes liable for payment for all of his or her treatment for the condition or complaint, the insurer shall provide on the explanation of benefits form a detailed explanation of the clinical rationale and of the basis in the policy, plan, or contract or in applicable law for the insurer’s restriction or termination of coverage.