Wisconsin Statutes Taxation (Ch. 70 to 79) § 77.93. Applicability

(1) All corporations required to file a return under subch. IV or V of ch. 71 that have at least $4,000,000 in gross receipts from all activities for the taxable year except corporations that are exempt from taxation under s. 71.26(1) and that have no unrelated business income reportable under s. 71.24(1m). The surcharge is imposed on the tax-option corporation, not on its shareholders, except that if a tax-option corporation's surcharge is delinquent, its shareholders are jointly and severally liable for it.

(4) All insurers that are required to file a return under subch. VII of ch. 71 and that have at least $4,000,000 in gross receipts from all activities for the taxable year.