No Section 301 tariffs Mexico are yet in force, but the picture changed on June 2, 2026. That day, USTR issued its determination in the forced-labor Section 301 investigation and proposed additional duties on 60 economies. Mexico was placed in the 10% tier. The duties are a proposal, not yet effective: written comments are due July 6, 2026 and USTR holds a public hearing on July 7, 2026. Critically, per Mexico’s Secretaría de Economía following consultations with USTR, goods that qualify under USMCA rules of origin are exempt — about 85% of Mexico’s export volume — and goods already covered by Section 232 (autos, steel, aluminum) are unaffected. As of this update no Section 301 tariffs are collected on Mexican-origin goods.
No Section 301 tariffs are collected on Mexican-origin goods as of this update. On June 2, 2026, USTR proposed a 10% Section 301 forced-labor duty on Mexico, now in a public-comment period (comments due July 6, hearing July 7) and not yet in effect. Section 232 (steel/aluminum/autos) and Section 122 (temporary surcharge) duties apply separately and are covered below.
Section 301 of the Trade Act of 1974 gives the U.S. Trade Representative authority to impose tariffs in response to foreign trade practices it deems unfair. The statute is the legal foundation of the U.S. tariff program against Chinese imports that began in 2018, when the first Trump administration used Section 301 to impose duties on roughly $370 billion of Chinese goods across four product lists. It remains the largest single tariff program in U.S. history.
Section 301 tariffs operate under a different statute than Section 232 tariffs. Section 232 covers imports deemed a national security risk (the current 25 percent tariff on steel and aluminum imports falls under Section 232). Section 301 covers trade practices deemed unfair. Mexico is currently subject to Section 232 on steel and aluminum, but is not currently subject to any Section 301 tariffs. That distinction is the answer most North American manufacturing executives are searching for when they ask about Section 301 tariffs Mexico in May 2026.
One regulatory note that matters for planning. Section 301 was not affected by the Supreme Court ruling in 2025 that struck down a parallel tariff program built on the International Emergency Economic Powers Act (IEEPA). Section 301 sits under the Trade Act of 1974, which has independent statutory footing. The tool USTR has used continuously against China since 2018 is the same tool now under consideration for Mexico.
A Section 301 action moves through five formal steps. Knowing the sequence is what allows operators to engage the process rather than read to it after the fact.
The procedural rigor is what gives Section 301 its durability. Each step builds a record that has been upheld against legal challenge.
The administration has used three different statutory bases to impose tariffs since 2025. Each has different scope, durability, and legal footing. Knowing which mechanism is active matters operationally, because each one carries different exemptions and timelines.
The progression matters. When IEEPA was struck down in 2025, Section 122 became the temporary bridge mechanism. When Section 122 expires on July 24, 2026 (or sooner if the Court of International Trade ruling holds on appeal), Section 301 is positioned to take over as the durable instrument. The same day Section 122 statutorily expires is the day USTR’s Section 301 determinations are expected. That alignment is not a coincidence.
The chronology that brought Section 301 tariffs Mexico from theoretical to active question:
The China-origin schedule remains active and is the operational reference point for any future Section 301 action against Mexican-origin goods. As of May 2026, the rates read as follows:
178 product-specific exclusions remain active. They were extended through November 10, 2026 following the meeting between Presidents Trump and Xi on November 1, 2025. After that date, exclusion renewal is not guaranteed.
On March 11 and 12, 2026, USTR opened two new Section 301 investigations. For the first time since the statute was first used against China in 2018, Mexico is among the named targets.
Targets 16 economies including China, Mexico, Brazil, India, Vietnam, Thailand, Indonesia, Turkey, the European Union, Japan, South Korea, Taiwan, Malaysia, the United Arab Emirates, Saudi Arabia, and Argentina. The named sectors include steel, aluminum, semiconductors, electric vehicles, solar cells, batteries, and critical minerals.
Covered 60 economies, including Mexico. On June 2, 2026 USTR completed this investigation and found all 60 economies actionable. Mexico was among six (Canada, Ecuador, the EU, Indonesia, Mexico, Pakistan) found to have “failed to effectively enforce” a forced-labor import prohibition — a notch below the 54 economies found to have failed to impose and enforce one. USTR’s stated concern is the effective enforcement of forced-labor import bans broadly; Chinese-owned production in Mexico sourcing from regions flagged under the Uyghur Forced Labor Prevention Act remains a related exposure for individual supply chains.
The forced-labor determination was issued June 2, 2026, ahead of the July 24 date. The excess-capacity determination is still expected around July 24, 2026 — the same day the Section 122 surcharge statutorily expires. The alignment positions Section 301 to become the operative tariff mechanism the moment Section 122 expires.
That date is not arbitrary. July 24, 2026 is also the statutory expiration of the Section 122 temporary surcharge currently in force. The alignment positions Section 301 to become the operative tariff mechanism the moment Section 122 expires, or sooner if the Court of International Trade ruling holds on appeal.
The investigations themselves were prompted by USTR analysis of post-2018 trade and investment patterns, including the tripling of Chinese foreign direct investment into Mexico between 2020 and 2024 as Chinese-owned companies built plants in Nuevo León, Coahuila, Querétaro, and Aguascalientes to serve the U.S. market under USMCA preference. Mexico displaced China as the United States’ top trading partner in 2023 and has held that position through Q1 2026. That structural shift, often described as binational nearshoring, is what brought the question of Section 301 tariffs Mexico from theoretical to active.
USTR has discretion in how Section 301 tariffs are designed if a determination supports them. Three patterns from the China program offer the most useful guide:
Emilio Cadena, CEO of Prodensa, frames the size of the duty differential that any new Section 301 tariffs on Mexico would create:
“Previously, the cost of importing to the US outside of the treaty was between 2.5% and 3.5% (WTO tariffs); today, that differential can fluctuate between 10% and 25%. Producing under the USMCA framework is the most competitive option for both Mexico and the United States. By shifting production from Asia to Mexico, the US economy benefits directly, because for every dollar produced in our country, the integration of inputs and components originating from the United States increases significantly.”
Emilio Cadena, CEO, Prodensa
The defense against Section 301 tariffs Mexico exposure is USMCA compliance. Goods that qualify under USMCA rules of origin enter the U.S. at zero percent. Goods that do not qualify face whatever rates emerge from the USTR process.
The window between this update and the July 24, 2026 determination is the time to map exposure. Whether the question is current Section 232 duties or future Section 301 tariffs Mexico, the defense is the same: documentation, discipline, and binational coordination. Cadena puts the current size of the exposure in operational terms: “About 30% of exports to the United States pay some form of tariff due to non-compliance with USMCA rules or because they are subject to Section 232.” The work to bring that share down is not theoretical:
Before any USTR determination opens the door to enforcement, your rules-of-origin file should be defensible end to end. Regional value content calculations, supplier certifications, and tariff classifications all need to hold up under scrutiny they have not yet faced.
If any supplier in your bill of materials has Chinese ownership or sources critical inputs from China, document it. Plan for the contingency that those tiers may face additional duty, require reclassification, or trigger forced-labor questions under the parallel investigation.
“North American supply chains are increasingly integrated, with manufacturers investing significant resources to comply with USMCA rules of origin and regional production requirements. When companies meet those requirements, the agreement should deliver on its core promise: predictable, tariff-free trade within the region. Trade measures designed to address external competition should focus on imports from outside North America, ensuring that USMCA compliance continues to strengthen, rather than complicate, regional manufacturing integration.”
Emilio Cadena, CEO, Prodensa
Tariffs imposed by the U.S. government under the Trade Act of 1974 in response to trade practices considered unfair or harmful to U.S. commerce.
Trade measures tied to national security concerns, currently applied to products such as steel and aluminum imports.
Requirements used to determine whether a product qualifies for preferential tariff treatment under the USMCA.
A USTR investigation focused on identifying supply chains or manufacturing operations potentially linked to forced labor practices.
Not yet collected, but proposed. On June 2, 2026 USTR completed the forced-labor Section 301 investigation and proposed a 10% additional duty on Mexican-origin goods. It is in a public-comment phase (comments due July 6, hearing July 7) and not in effect. Per Mexico’s Secretaría de Economía, USMCA-qualifying goods (~85% of export volume) are exempt and Section 232 goods (autos, steel, aluminum) are unaffected.
USTR found all 60 economies in the forced-labor investigation actionable under Section 301 and proposed additional duties: 10% on economies that have a forced-labor import prohibition or a partial/committed regime (Mexico’s tier) and 12.5% on the rest, plus a reduced-rate textile mechanism. The proposal excludes products listed in Annex A of the Federal Register notice. Mexico’s government states that USMCA-qualifying goods are exempt. The measure is open for written comment through July 6, 2026, with a hearing July 7, 2026, and is not yet in force.
Section 232 of the Trade Expansion Act of 1962 covers imports deemed a national security risk. The current 25 percent U.S. tariff on steel and aluminum imports falls under Section 232 and does apply to Mexican-origin goods. Section 301 of the Trade Act of 1974 covers trade practices deemed unfair. Mexico is not currently subject to any Section 301 tariffs.
Section 122 of the Trade Act of 1974 authorizes a temporary import surcharge up to 15 percent ad valorem for up to 150 days in response to fundamental international payments problems. The administration imposed a 10 percent Section 122 surcharge effective February 24, 2026. It applies to Mexican-origin goods that do not qualify under USMCA. USMCA-qualifying goods are exempt. Section 122 is scheduled to expire July 24, 2026, and was ruled unlawful by the U.S. Court of International Trade on May 8, 2026 (under appeal).
Two things happen on July 24, 2026. First, the Section 122 temporary surcharge statutorily expires at the 150-day limit. Second, USTR Section 301 determinations from the March 2026 investigations are expected. The alignment means Section 301 is positioned to take over as the operative tariff mechanism the moment Section 122 expires.
IEEPA tariffs were vacated by the Supreme Court in 2025 because the Court found the statute did not authorize the President to impose tariffs in the manner used. Section 301 sits under a different statute (the Trade Act of 1974) with explicit congressional grant of tariff authority to USTR after a formal investigation. The procedural rigor of the Section 301 process, including public comment and hearings, is what gives the tool its legal durability.
For the forced-labor investigation, USTR already decided: it determined Mexico actionable and proposed a 10% duty on June 2, 2026. A final action follows the July 6 comment deadline and July 7 hearing. The separate excess-capacity investigation determination is still expected around July 24, 2026.
The excess-capacity investigation names steel, aluminum, semiconductors, electric vehicles, solar cells, batteries, and critical minerals. These are the same strategic sectors that already carry elevated Section 301 rates on Chinese imports.
Prodensa has been the operating partner for foreign manufacturers in Mexico since 1985, and Section 301 exposure is the kind of question we have been answering for four decades. Our trade advisory team and institutional relations advisors support global clients on a daily basis to stay informed and competitive.
Sources:
Federal Registrar: Imposing a Temporary Import Surcharge
Congress.gov: Section 122 of the Trade Act of 1974
White & Case: Trump Administration Imposes 10% Section 122 Tariff in Plan to Replace IEEPA Tariffs
Global Trade Alert: From IEEPA to Section 122
USTR: Findings and Proposed Action in 60 Section 301 Forced Labor Investigations (June 2, 2026)
USTR: Report on Forced Labor Import Ban Findings (June 2, 2026)
Secretaría de Economía (México), Comunicado 44, June 3, 2026 (proposal does not cover T-MEC–compliant trade).
Note- this article was supported by AI productivity tools.