Legislative Branch Appropriations Act, 2018 Provides FY2018 appropriations for the legislative branch, including the Senate and Joint Items such as: the Joint Economic Committee, the Joint Committee on Taxation, the Office of the Attending Physician, and the Office of Congressional Accessibility Services. Provides FY2018 appropriations for: the Capitol Police; the Office of Compliance; the Congressional Budget Office; the Architect of the Capitol; the Library of Congress, including the Congressional Research Service (CRS) and the Copyright Office; the Government Publishing Office (GPO); the Government Accountability Office; the Open World Leadership Center Trust Fund; and the John C. Stennis Center for Public Service Training and Development. Requires certain CRS reports to be made available to the public using a GPO website. (Pursuant to the longstanding practice of each chamber of Congress determining its own requirements, funds for the House are not included in the Senate bill.) Sets forth permissible and prohibited uses for funds provided by this bill.