Stigler Act Amendments of 2018 This bill amends the Act of August 4, 1947 (commonly known as the Stigler Act) to revise the qualifications that must be met for inherited land to remain in restricted status. When land is in restricted status, it is not subject to taxation and may not be sold or transferred without permission of the Department of the Interior. Under current law, the restricted status of land allotted to the Five Civilized Tribes of Oklahoma is maintained only if the individual holding title has at least 50% Indian blood from one of the Five Tribes (the Choctaw, Chickasaw, Creek, Cherokee, and Seminole tribes). This bill removes this requirement, thus, the restricted status is maintained for lineal descendants of an original enrollee whose name appears on the membership rolls of the Five Tribes.