Tribal Economic Assistance Act of 2017 This bill amends the Internal Revenue Code to extend and modify several tax provisions relating to Indian reservations. The bill: repeals a provision that limits an Indian tribal government's eligibility for certain excise tax exemptions to transactions involving the exercise of an essential government function; makes permanent the special depreciation rules for property used predominantly within an Indian reservation; makes permanent the Indian employment tax credit; requires the Department of the Treasury to give priority to qualified low-income community investments on Indian reservations when allocating new markets tax credits; and allows qualified school construction bonds allocated for schools funded by the Bureau of Indian Affairs to be used for reasonable and necessary predevelopment costs directly associated with the construction, rehabilitation, or repair of a school. The bill also amends the Indian Self-Determination and Education Assistance Act to establish a federal escrow account to carry out a qualified Indian school construction bond program for schools funded by the Bureau of Indian Affairs.