1. Short title This Act may be cited as the Tribal Social Security Fairness Act of 2018 . 2. Voluntary agreements for coverage of services by American Indian tribal council members (a) In general Title II of the Social Security Act ( 42 U.S.C. 401 et seq.) is amended by inserting after section 218 the following new section: 218A. Voluntary agreements for coverage of Indian tribal council members (a) Purpose of agreement (1) The Commissioner of Social Security shall, at the request of any Indian tribe, enter into an agreement with such Indian tribe for the purpose of extending the insurance system established by this title to services performed by individuals as members of such Indian tribe's tribal council. Any agreement with an Indian tribe under this section applies to all members of the tribal council, and shall include all services performed by individuals in their capacity as council members. (2) Notwithstanding section 210(a), for the purposes of this title, the term employment includes any service included under an agreement entered into under this section. (b) Definitions For the purposes of this section: (1) The term member means, with respect to a tribal council, an individual serving as a member or the head of the tribal council. (2) The term tribal council means the governing body of a federally recognized Indian tribe. (c) Effective date of agreement (1) Any agreement under this section shall be effective with respect to services performed after an effective date specified in such agreement, provided that such date may not be earlier than the first day of the next calendar month after the month in which the agreement is executed by both parties. (2) At the request of the Indian tribe at the time of the agreement, such agreement may apply with respect to services performed before such effective date for which there were timely paid in good faith (and not subsequently refunded) to the Secretary of the Treasury amounts equivalent to the sum of the taxes which would have been imposed by sections 3101