1. Extension of Generalized System of Preferences (a) In general Section 505 of the Trade Act of 1974 ( 19 U.S.C. 2465 ) is amended by striking December 31, 2017 and inserting December 31, 2020 . (b) Effective date (1) In general The amendment made by subsection (a) shall apply to articles entered on or after the 30th day after the date of the enactment of this Act. (2) Retroactive application for certain liquidations and reliquidations (A) In general Notwithstanding section 514 of the Tariff Act of 1930 ( 19 U.S.C. 1514 ) or any other provision of law and subject to subparagraph (B), any entry of a covered article to which duty-free treatment or other preferential treatment under title V of the Trade Act of 1974 ( 19 U.S.C. 2461 et seq.) would have applied if the entry had been made on December 31, 2017, that was made— (i) after December 31, 2017, and (ii) before the effective date specified in paragraph (1), shall be liquidated or reliquidated as though such entry occurred on the effective date specified in paragraph (1). (B) Requests A liquidation or reliquidation may be made under subparagraph (A) with respect to an entry only if a request therefor is filed with U.S. Customs and Border Protection not later than 180 days after the date of the enactment of this Act that contains sufficient information to enable U.S. Customs and Border Protection— (i) to locate the entry; or (ii) to reconstruct the entry if it cannot be located. (C) Payment of amounts owed Any amounts owed by the United States pursuant to the liquidation or reliquidation of an entry of a covered article under subparagraph (A) shall be paid, without interest, not later than 90 days after the date of the liquidation or reliquidation (as the case may be). (3) Definitions In this subsection: (A) Covered article The term covered article means an article from a country that is a beneficiary developing country under title V of the Trade Act of 1974 ( 19 U.S.C. 2461 et seq.) as of the effective date specified in paragraph (1). (B) Enter