According to the legislation signed by the President of the USA reauthorizing the Generalized System of Preferences (GSP) program for Armenia, April 22, 2018 is the effective date of the reauthorization.

GSP-eligible products may enter the U.S. with reduced or zero rates.

As the GSP program’s reauthorization is retroactive, importers may seek refunds of duties paid during the lapse (January 1, 2018 - April 22, 2018) of GSP authorization. . To receive a GSP duty refund, an importer has to file a request by October 19, 2018.”