(a) A surcharge is imposed on each authorized insurer with gross premiums subject to the surcharge under Section 255.003, including a:
(1) stock insurance company;
(2) mutual insurance company;
(3) reciprocal or interinsurance exchange; and
(4) Lloyd's plan.
(b) The surcharge required by this chapter is in addition to taxes or other surcharges imposed that are not in conflict with this chapter.