Mexico's retaliatory tariffs on US exports

Mexico’s response under the USMCA

Mexico’s retaliatory tariffs on US exports are administered through a presidential decree — a Decreto— issued by the federal executive and published in the Diario Oficial de la Federación, the country’s official gazette, with the Secretaría de Economía responsible for the trade-policy detail. Unlike the long-running Chinese schedule or the metals-driven European package, Mexico’s 2025 measures have a distinctly agricultural centre of gravity, reflecting the deep cross-border trade in grain and the political weight of farm goods in the bilateral relationship. The rates and targeted lines on this page are taken from the International Trade Administration Foreign Retaliations Database, verified for these entries in May 2026. Because the exact Decreto reference is still being confirmed against the Diario Oficial as part of a later legal review, the database serves as the primary citation and the official gazette is named here as the authority of record rather than linked directly.

The corn surtax

The steepest charge Mexico applies is a fifty percent surtax on US yellow corn, classified under Harmonised System heading 1005.90 and effective March 15, 2025. That figure is the highest flat retaliatory rate among the major US trading partners tracked on this site, and it lands on one of the largest single agricultural flows in North America: US Midwest grain moving south to feed Mexican livestock and food processing. For an American corn exporter, a fifty percent charge is not a marginal cost of doing business — it is large enough to reroute trade entirely, favouring alternative suppliers or pushing Mexican buyers toward domestic production. The agricultural focus distinguishes Mexico from the other retaliating partners, whose 2025 measures concentrated on industrial metals, vehicles, and consumer goods.

The steel surtax

Alongside the corn measure, Mexico applied a twenty-five percent surtax to US-origin steel flat products under heading 7208.52 and related Chapter 72 lines, also effective March 15, 2025. This charge was the direct counterpart to the US Section 232 steel duties, mirroring the metals-for-metals logic seen in the Canadian and European responses but delivered through Mexico’s own decree mechanism. The pairing of a very high agricultural rate with a more conventional metals rate is characteristic of how Mexico structured its package: a headline-grabbing farm measure with clear domestic resonance, accompanied by a proportionate industrial response to the specific US action that prompted it.

Where the authority sits

Both surtaxes flow from the executive branch rather than the legislature. A Decreto signed at the presidential level and published in the Diario Oficial de la Federación carries immediate legal force, and the Secretaría de Economía manages the operational detail of which tariff lines are covered and how the surtax is collected at the border. Like Canada, Mexico structured its measures around the regional trade agreement: the charges are written to fall on shipments that do not qualify under the USMCA rules-of-origin, leaving qualifying North-American-content goods on a different footing. That parallel is not a coincidence — both countries share the same continental agreement with the United States and have converged on a similar exemption architecture, even though each uses its own domestic legal instrument to impose the duty.

What US exporters should watch

The exposure is concentrated and regional. US grain exporters — especially corn growers and the elevators and traders who move Midwest production south — carry the heaviest burden under the fifty percent corn surtax, and for them the Mexican market is large enough that the measure reshapes planting and marketing decisions, not just a single season’s shipments. Steel producers selling flat products into Mexico face the more familiar twenty-five percent metals charge. For both groups, the key variable is whether a shipment can establish USMCA-qualifying status, since the measures are written to target non-qualifying trade. The broader outlook tracks the health of the North American trade relationship and the periodic reviews of the agreement, which set the political temperature for whether these decrees are widened, narrowed, or left in place.

Why the corn line carries such weight

To understand why a surtax on a single grain commands this much attention, it helps to see the scale of the trade behind it. Mexico is the largest foreign buyer of US corn, and the flow is overwhelmingly yellow corn destined for animal feed in the Mexican livestock and poultry sectors. That dependence runs in both directions: US growers rely on the Mexican market to absorb a substantial share of the crop, and Mexican feedlots rely on US grain to hold down protein costs. A fifty percent surtax inserted into that relationship is less a marginal duty than a structural shock — it changes the arithmetic for grain traders, elevator operators, and the railroads and barges that move the crop south, and it gives domestic Mexican production and alternative exporters an opening they would not otherwise have.

The decree mechanism amplifies that effect by acting quickly. Because a Decreto takes legal force on publication in the official gazette, a surtax can appear with far less lead time than a US tariff proceeding, which typically runs through notice-and-comment periods before taking effect. For a US agricultural exporter, that speed is the operative risk: a measure can be in force before a shipment already in transit clears customs, so contracts into the Mexican market increasingly allocate tariff risk explicitly rather than assuming a stable duty environment. The pairing of a fast legal instrument with a high headline rate on a commodity this central is what makes the Mexican corn measure the most consequential single agricultural line in the entire retaliation landscape.

Verifying a specific rate

To confirm a Mexican measure for a particular US export, locate the product in the Foreign Retaliations Database by Harmonised System code and note the rate and effective date. For the operative legal text, the authority of record is the Decreto as published in the Diario Oficial de la Federación, with the Secretaría de Economía as the administering body; the precise Decreto number for these 2025 measures is being confirmed against the official gazette in a later legal review, so an exporter relying on the exact citation should check the current Diario Oficial publication directly. The figures here reflect the database as verified in May 2026; for a binding transaction, confirm the current decree and the USMCA status of the shipment with a licensed customs broker in Mexico.