the Highway Trust Fund that is not the Mass Transit Account. (3) Mass Transit Account The term Mass Transit Account means the portion of the Highway Trust Fund established under section 9503(e)(1) of the Internal Revenue Code of 1986. 1002. Extension of highway trust fund expenditure authority Section 9503 of the Internal Revenue Code of 1986 is amended— (a) by striking October 1, 2020 in subsections (b)(6)(B), (c)(1), and (e)(3) and inserting October 1, 2021