New U.S. Tariffs on Mexico Are Piling Up — and USMCA Doesn't Fully Protect Against Them
USMCA was supposed to lock in preferential market access between the United States, Mexico, and Canada. The current U.S. tariff posture is testing just how durable that framework is.
As of February 24, 2026, U.S. imports from Mexico are subject to a 10% tariff imposed under Section 122 of the Trade Act of 1974, valid for up to 150 days. The measure includes a carve-out for goods that qualify under USMCA rules of origin — meaning products that meet the agreement’s domestic content requirements can avoid the levy — but that exception does not cover everything crossing the border.
The Section 122 tariff is not the only layer. Section 232 of the Trade Expansion Act of 1962, which allows tariffs to be imposed on national security grounds, has been used to apply duties on U.S. imports of autos and auto parts, steel, aluminum, and copper from Mexico. These sectors are among the most economically significant in bilateral trade, making the impact substantial. Motor vehicles and auto parts alone accounted for over $150 billion in U.S. imports from Mexico in 2025.
Now additional exposure is opening. In February 2026, the administration launched two Section 301 investigations — one targeting excess industrial capacity, the other focusing on imports made with forced labor. Section 301 has historically been the vehicle for broad punitive tariffs; its application to Mexico, if investigations conclude with action, could add another tier of duties on top of what already exists.
The cumulative effect is a tariff architecture that pulls in two directions simultaneously: USMCA promises preferential treatment, while executive branch trade authorities carve out exceptions that can cover precisely the sectors USMCA was designed to integrate. For businesses operating cross-border supply chains — particularly in autos and electronics — the compliance calculus has grown considerably more complicated since the agreement entered into force in 2020.