On March 18, 2021, U.S. Customs and Border Protection (CBP) published an addendum to the implementation instructions for the United States – Mexico – Canada Agreement (USMCA) in Spanish and French. The addendum was originally published in English in January 2021. It includes several updates, including the treatment of goods entering through foreign trade zones (FTZ) and merchandise processing fee (MPF) refunds on post importation claims. The updates are effective retroactively to July 1, 2020. The restrained enforcement period for USMCA ended on December 31, 2020.
The addendum can be found in English, Spanish, and French here: