The US-Mexico-Canada Agreement (USMCA) went into force on July 1, 2020 replacing NAFTA. As traders know, shipping to/from Mexico is a bit more complicated than to/from Canada. In general the services of a Mexican customs broker are needed and shipments need to be transferred between US and Mexican carriers at specific ports of entry.
Some NAFTA provisions remain in effect but USMCA does contain new regulations as well. Here is a link to FAQs from the CBP website.
https://www.cbp.gov/trade/priority-issues/trade-agreements/free-trade-agreements/USMCA/FAQs
Contact mitch@52.91.45.227 for more info.