49, United States Code, is amended by adding at the end the following: (3) Additional authorization of appropriations There shall be available from the Mass Transit Account of the Highway Trust Fund for fiscal years 2021 through 2029 such funds as are specifically allocated for those fiscal years under paragraph (2). Nothing in this paragraph shall be construed to authorize the appropriation of any amounts not so allocated. . (2) Conforming amendment Section 5338(a)(2) of title 49, United States Code, is amended by inserting or paragraph (3) after paragraph (1) . (b) Low- and No-Emission Component Assessment Program Section 5338(a)(2)(G) of title 49, United States Code, is amended to read as follows: (G) $28,000,000 for each of fiscal years 2016 through 2019 and $45,000,000 for each of fiscal years 2020 through 2029 shall be available to carry out section 5312, of which— (i) $3,000,000 for each of fiscal years 2016 through 2019 and $5,000,000 for each of fiscal years 2020 through 2029 shall be available to carry out section 5312(h)