Iowa Code § 432A.1
Every insurer authorized to do the business of selling marine insurance in this state, as authorized in section 515.48, shall, with respect to all insurance written within this state upon hulls, freights, or disbursements, or upon goods, wares, merchandise and all other personal property and interests therein, in the course of exportation from or importation into any country, or transportation coastwise including transportation by land or water from point of origin to final destination in respect to or appertaining to or in connection with, any and all risks or perils of navigation, transit or transportation and upon the property while being prepared for and while awaiting shipment, and during any delays, storage, transshipment or reshipment incident thereto, including war risks and marine builder's risks, pay a tax of six and one-half percent on its taxable underwriting profit ascertained as provided in section 432A.2, from such insurance written within this state.
Iowa Code § 432A.1