77 Pa. Stat. § 1036.17
Any group of five (5) homogeneous employers who will provide to the fund an annual volume of premium of at least five hundred thousand dollars ($500,000) may become subscribers as a group to the State Workmen's Insurance Fund for the purpose of insuring therein their liability to those of their employes. Such group shall become legally obligated to pay any employe compensation required by this act because of bodily injury by accident or disease, including death at any time resulting therefrom, sustained by such employe arising out of and in the course of his employment. Such group shall make a written application for subscription for group insurance to the board. Such application shall designate the name of the group subscriber and shall include such information as determined by the board as will allow the board to identify the employers and to adequately assess risks and premiums to be charged to employers to be insured by the fund under the group subscription.
77 P.S. § 1036.17