1. Short title This Act may be cited as the Multinational Species Conservation Funds Semipostal Stamp Reauthorization Act of 2019 . 2. Reauthorization; requirement to sell all stamps (a) In general Section 2(c) of the Multinational Species Conservation Funds Semipostal Stamp Act of 2010 ( 39 U.S.C. 416 note; Public Law 111–241 ) is amended— (1) in paragraph (2)— (A) by striking of at least 6 years, ; and (B) by inserting before the period at the end the following: and ending not earlier than the date on which the United States Postal Service provides notice to Congress under paragraph (5) ; and (2) by adding at the end the following: (5) Requirement to sell all stamps printed (A) In general The United States Postal Service shall sell each copy of the Multinational Species Conservation Fund Semipostal Stamp that the United States Postal Service prints under this Act. (B) Notification of Congress The United States Postal Service shall notify the Committee on Homeland Security and Governmental Affairs of the Senate and the Committee on Oversight and Reform of the House of Representatives when all copies of the Multinational Species Conservation Fund Semipostal Stamp printed under this Act have been sold. . (b) Retroactive applicability (1) In general The amendments made by subsection (a) shall take effect as if enacted on the day after the date of enactment of the Multinational Species Conservation Funds Semipostal Stamp Reauthorization Act of 2013 ( Public Law 113–165 ; 128 Stat. 1878). (2) Consequence of destruction of stamps If the United States Postal Service destroys 1 or more Multinational Species Conservation Fund Semipostal Stamps before the date of enactment of this Act, the United States Postal Service shall print and sell the same number of such stamps on or after that date of enactment.