International Insurance Standards Act of 2018 (Sec. 3) This bill prohibits parties representing the federal government in an international insurance agreement from agreeing to any standard unless it recognizes the existing U.S. system of regulation as satisfying that standard. (Sec. 4) In developing international insurance standards, the parties must coordinate with state insurance regulators. (Sec. 5) Parties representing the United States in such proceedings must consult with and notify Congress regarding the intention to participate in the negotiations, the nature and objectives of the negotiations, and the details of the agreement. (Sec. 6) Before entering into any agreement, the parties must report to Congress regarding the implementation and impact of the agreement. (Sec. 7) The bill amends the Federal Insurance Office Act of 2010 to modify requirements for an international agreement entered into by the Department of the Treasury's Federal Insurance Office. Such an agreement must only apply on a prospective basis. In developing an agreement, the parties must coordinate with state insurance regulators. Congress has the power to review and disapprove by joint resolution any agreement.