In March 2026, USTR opened Section 301 investigations into structural excess capacity across manufacturing sectors in 16+ economies. With Section 122 expiring July 24, 2026, these investigations are widely viewed as the administration's vehicle for permanent replacement tariff authority. Here's who's under the microscope — and what it means for your supply chain.
On or around March 11, 2026, the United States Trade Representative formally initiated Section 301 investigations targeting structural excess capacity in manufacturing sectors across 16+ economies. These investigations were launched under Section 301 of the Trade Act of 1974, which authorizes USTR to investigate and respond to foreign government policies and practices that are "unreasonable or discriminatory" and burden or restrict US commerce.
The central theory of harm: foreign governments have deployed industrial policy — subsidies, state-directed lending, production mandates, and below-market input pricing — to artificially expand manufacturing capacity far beyond domestic consumption. The resulting flood of exports into global markets, and into the United States specifically, has displaced American producers and distorted competition. USTR is treating this as an actionable unfair trade practice under Section 301.
This is a broader framing than prior Section 301 actions. Rather than targeting a specific product (like solar cells in 2012) or a single country (China in 2018–2019), the March 2026 investigations are cross-sectoral and multi-country. Steel, aluminum downstream products, electronics, chemicals, textiles, automotive components, and industrial machinery are all in scope.
Section 301 was last used aggressively in 2018–2019 when the Trump administration imposed tariffs on roughly $370 billion of Chinese goods across four product lists. Those tariffs remain in effect as of March 2026, with rates ranging from 7.5% (List 4B) to 25% on most goods (Lists 1–3), and up to 100% on targeted categories like electric vehicles. The new 2026 investigations could expand this framework to new countries and additional product categories.
Section 122 tariffs — imposed in February 2026 — carry a statutory 150-day sunset. The administration cannot keep them in place indefinitely without Congressional authorization, and Congress has not moved to extend them. Section 301 carries no equivalent time limit. Once a Section 301 tariff determination is made, the tariffs remain until USTR modifies or revokes them through a formal proceeding. That's why the March 2026 investigations matter: they're building the legal foundation for tariffs that could last years, not months.
Additionally, Section 301 enables surgical targeting. The statute allows USTR to impose tariffs on specific HTS codes, specific product categories, and specific countries — or combinations thereof. Section 122 applies broadly. Section 301 can be structured to pressure specific supply chains while leaving others intact.
The following countries were identified in USTR's March 2026 investigative actions as having manufacturing sectors under review for excess capacity and unfair trade practices. Investigation intensity and sector focus vary significantly by country. China faces the broadest and most advanced review, given the existing Section 301 framework already in place.
⚠️ Analysis note: "Investigation stage" and risk ratings represent USTradeStack analysis based on USTR announcements and public filings. They are not official USTR determinations. Actual tariff outcomes depend on formal investigative findings.
| Economy | Primary Sectors Under Review | Investigation Stage | Risk Assessment |
|---|---|---|---|
| 🇨🇳 China | Steel, Electronics, Solar, EVs, Textiles, Chemicals, Machinery | Advanced — extends existing Lists 1–4 | ● High |
| 🇩🇪🇫🇷🇮🇹 EU (Germany, France, Italy, Spain) | Steel, Automotive Components, Chemicals, Industrial Machinery | Active investigation initiated | ● Medium |
| 🇯🇵 Japan | Steel, Automotive, Semiconductor Equipment | Active investigation initiated | ● Medium |
| 🇰🇷 South Korea | Steel, Semiconductors, Display Panels, Petrochemicals | Active investigation initiated | ● Medium |
| 🇻🇳 Vietnam | Textiles, Electronics Assembly, Furniture, Footwear | Active investigation — circumvention concerns elevated | ● High |
| 🇮🇳 India | Pharmaceuticals, Textiles, Steel, Chemicals | Active investigation initiated | ● Medium |
| 🇲🇽 Mexico | Automotive, Steel, Electronics (circumvention review) | Active — USMCA compliance overlay complicates action | ● Low–Medium |
| 🇹🇼 Taiwan | Semiconductors, Electronics, Petrochemicals, Steel | Under review — strategic ally considerations apply | ● Low–Medium |
| 🇹🇭 Thailand | Automotive Parts, Textiles, Electronics Assembly | Initial inquiry stage | ● Low |
| 🇮🇩 Indonesia | Nickel, Steel, Palm Oil Chemicals, Textiles | Initial inquiry stage | ● Low |
| 🇧🇷 Brazil | Steel, Chemicals, Agricultural Inputs | Initial inquiry stage | ● Watch |
| 🇲🇾 Malaysia | Electronics, Semiconductors, Rubber Products | Initial inquiry — circumvention review | ● Low |
| 🇹🇷 Turkey | Steel, Textiles, Automotive | Initial inquiry stage | ● Watch |
| 🇨🇦 Canada | Aluminum, Steel, Softwood Lumber (separate track) | Under review — USMCA constraints limit Section 301 scope | ● Watch |
| 🇧🇩 Bangladesh | Textiles, Apparel, Footwear | Initial inquiry stage | ● Watch |
| 🇰🇭 Cambodia | Textiles, Footwear, Electronics Assembly | Initial inquiry — circumvention concerns | ● Low |
Click any cell for details. Colors indicate estimated tariff action risk based on USTR investigation focus areas. Analysis only — not official USTR determinations.
| Country | Steel & Metals | Electronics | Solar / Clean Energy | Automotive / EVs | Textiles & Apparel | Chemicals | Machinery | Medical Devices |
|---|
Risk levels reflect USTradeStack analysis of USTR investigation scope and historical Section 301 precedent. Not a prediction of final tariff actions.
Section 301 of the Trade Act of 1974 grants the USTR broad authority to investigate foreign government actions, policies, or practices that are "unreasonable or discriminatory" and burden or restrict US commerce. When USTR determines such a practice exists, it has authority to take "all appropriate and feasible action" — including imposing tariffs, duties, or other import restrictions — to eliminate the unfair trade practice or obtain compensation for US interests.
Based on USTR's stated focus on structural excess capacity in manufacturing, the following sectors face the greatest exposure to new Section 301 tariff actions:
Unlike Section 122 (150-day limit) or Section 201 (safeguard, typically 4 years), Section 301 tariffs have no statutory expiration. The China List 1–4 tariffs imposed in 2018–2019 are still in effect seven years later. Importers building sourcing strategies around Section 122 expiration must account for Section 301 permanence in their models.
Self-initiated investigations opened against 16+ economies. Federal Register notices expected to be published over the coming weeks specifying sectors and public comment windows.
Importers, manufacturers, and industry associations can file comments arguing for or against proposed tariff actions. This is the critical window to put your company's position on the record.
Formal public hearings expected for higher-priority investigations (China, Vietnam likely first). Testimony from importers, distributors, and domestic producers shapes the final record.
150-day statutory limit reached. Without Congressional action, Section 122 tariffs lapse. Whether Section 301 determinations are ready by this date remains uncertain — a coverage gap is possible.
Analysis suggests expedited timelines for advanced investigations (China, Vietnam). First tariff action notices could arrive as early as August–September 2026 for high-priority sectors.
Lower-priority investigations (EU, Japan, Korea) likely conclude in this window. New tariff schedules become effective 30 days after Federal Register publication of final determinations.
Model your Section 301 tariff exposure by country and product category. See how new duties would stack with your current cost structure.
The window between investigation launch and tariff determination is the highest-value period for supply chain action. Once USTR issues final determinations and tariffs take effect, your options narrow to paying the duty, finding exclusions (which take time and have uncertain outcomes), or scrambling to shift sourcing. Here's the strategic playbook:
Identify which of your sourcing countries are under Section 301 investigation. For each country, identify which product categories you import and cross-reference against the sector focus of the relevant investigation. Our Section 301 Exposure Calculator can give you instant estimates by country and product category.
Section 301 tariffs don't replace other duties — they stack on top of them. A product already subject to MFN duty rates, antidumping duties, and Section 232 metals tariffs could face Section 301 additions on top of all three. Use our Landed Cost Calculator to run worst-case duty scenarios with Section 301 factored in. Budget appropriately.
Every Section 301 investigation must be published in the Federal Register with a public comment period. This is your only formal opportunity to put your supply chain data on the record before USTR makes a determination. Companies that submit detailed economic impact comments — showing specific harm from tariff action — occasionally secure product-specific exclusions. Silence forfeits this opportunity entirely.
Not all sourcing shifts are equal. Diversifying from China to Vietnam has already been a well-traveled path — and Vietnam is now itself under investigation. Evaluate alternatives including nearshoring (Mexico, subject to USMCA rules), friendshoring (Taiwan, India — but watch those investigations too), and domestic sourcing. Lead times for qualifying new suppliers in lower-risk jurisdictions can run 12–24 months; start that process before tariffs hit.
If you import China-origin goods under existing Section 301 List 1–4 exclusions, verify their current status. Exclusions have expiration dates and must be renewed. The existing exclusion framework for China goods does not automatically extend to new investigations against other countries — new exclusion procedures would need to be established for each new tariff action.
Companies that waited until Section 301 tariffs on China took effect in 2018 faced 30–90 day supply chain gaps as they scrambled to shift sourcing. The time to act is during the investigation period — not after determinations are issued.
For comprehensive tariff modeling across all current and pending duty layers, use our Landed Cost Calculator. To check your specific country and product exposure, the Section 301 Tariff Exposure Calculator provides instant estimates.
In March 2026, USTR opened Section 301 investigations into structural excess capacity in manufacturing sectors across 16+ economies. These investigations examine whether foreign government subsidies and state-directed industrial policies constitute unfair trade practices under Section 301 of the Trade Act of 1974, which would justify US tariff retaliation.
Section 122 tariffs — imposed in February 2026 — carry a 150-day statutory time limit. Without Congressional extension, they lapse on July 24, 2026. Section 301 investigations are widely viewed as the administration's mechanism for permanent replacement tariff authority, as Section 301 carries no time limit. However, if Section 301 determinations are not finalized by July 24, there could be a brief gap in coverage.
Section 122 is time-limited to 150 days and applies broadly. Section 301 is permanent until formally modified, requires a specific finding of unfair trade practices, and can surgically target specific products and specific countries. Existing China Section 301 tariffs (Lists 1–4) imposed in 2018–2019 remain fully in effect today. Any new Section 301 tariffs would similarly persist until USTR initiates a formal modification proceeding.
Standard Section 301 investigations take 6–12 months from initiation through final determination. Given the July 24 deadline pressure, the administration has signaled intent to expedite high-priority investigations. China and Vietnam — the most advanced investigations — could see determinations as early as Q3 2026. EU, Japan, and Korea investigations are more complex and may extend into Q4 2026 or Q1 2027.
Yes — Section 301 tariffs stack on top of base MFN tariff rates, Section 232 steel/aluminum tariffs, and antidumping/countervailing duties. They do not stack with USMCA preferential rates for qualifying Canadian and Mexican goods. For some China-origin products, the combined duty burden (MFN + Section 232 + Section 301) can exceed 50–100% of customs value. Use our Landed Cost Calculator to model your specific situation.
Yes. Each Section 301 investigation includes a public comment period, published in the Federal Register. Importers, distributors, trade associations, and domestic manufacturers can submit written comments and request to testify at public hearings. This is the most important formal opportunity to influence the scope and structure of any resulting tariff action, including arguing for product-specific exclusions.
Potentially yes. Vietnam is under active Section 301 investigation, with USTR also examining circumvention concerns — whether Chinese goods are being minimally processed in Vietnam to avoid Section 301 tariffs. Importers who shifted from China to Vietnam post-2018 should closely monitor the Vietnam investigation and ensure their products genuinely qualify as Vietnam-origin under applicable rules of origin, not just transshipment/circumvention criteria.
Use these tools to model your Section 301 exposure and prepare for what comes after Section 122.