President Trump orders tariffs and price floors in polysilicon Section 232 action

On August 6, 2026, President Trump issued a proclamation imposing import restrictions under the Section 232 investigation of imports of polysilicon and its derivatives, mostly targeting downstream solar energy components.¹ Effective December 4, 2026, the United States will apply (1) a 15% ad valorem tariff on certain polysilicon derivative products, and (2) minimum import prices (MIPs) enforced through additional specific tariffs on polysilicon and polysilicon derivative products.

While the only downstream products targeted by the tariffs are solar energy components, the proclamation frames the action primarily around semiconductor supply-chain security, citing the decline in the US share of global polysilicon production capacity and the decline in US semiconductor wafer fabrication capacity. The solar-sector rationale is presented as a secondary but related basis, given that solar-grade polysilicon demand is described as necessary to sustain the production volumes and unit costs that keep semiconductor-grade polysilicon production commercially viable.

Entry into effect

The tariffs and minimum import prices will enter into effect for goods entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. Eastern Time on December 4, 2026.

Goods that claim entry under Chapter 98 provisions remain eligible for and subject to the terms of any such Chapter 98 provision.

Products subject to the tariffs admitted into a United States foreign trade zone on or after December 4, 2026 may be admitted only under "privileged foreign status," as described in 19 C.F.R. 146.41 (unless eligible for "domestic status"). Any product admitted in "privileged foreign status" before December 4, 2026 will be subject upon entry for consumption to any tariffs under the applicable HTSUS subheading.

Instructions to monitor for stockpiling

Due to the 120-day gap between announcement of the action and its implementation, the Trump administration appears concerned about the risk that companies may stockpile covered products in the United States to frontload the tariffs. To address that possibility, the proclamation instructs the Department of Commerce (Commerce) to monitor imports and provides that, if Commerce "determines that a company is stockpiling polysilicon or polysilicon derivatives" ahead of the tariffs' entry into effect, Commerce "shall take action in coordination with CBP to restrict imports by the company and its affiliates." However, the proclamation does not establish any specific enforcement measure, nor does it explain how Commerce should go about monitoring, what levels of imports would constitute "stockpiling," or what the remedial import restrictions would be. There is some risk that such a finding by Commerce could result in the retroactive application of tariffs to goods imported before December 4.

Products covered by the tariffs and MIPs

The tariffs and MIPs apply to polysilicon and certain "polysilicon derivatives," which include polysilicon ingots and wafers, and solar cells and modules. As discussed further below, polysilicon is subject only to the MIP mechanism and is not subject to the separate 15% ad valorem tariff, which applies only to the polysilicon derivative products.

• Polysilicon, as classified within HTSUS 2804.61.0000 (which is specifically high-purity, electronic- and solar-grade silicon that contains at least 99.99% silicon by actual weight).
• Polysilicon ingots and wafers, as classified within HTSUS 3818.00.0020, 3818.00.0040, 3818.00.0045, 3818.00.0050, and 3818.00.0091.
• Solar photovoltaic cells, as classified within HTSUS 8541.42.00 (described as HTSUS 8541.42.0010 and 8541.42.0080 in Annex I of the proclamation).
• Solar photovoltaic modules, as classified within HTSUS 8541.43.00 (described as HTSUS 8541.43.0010 and 8541.43.0080 in Annex I of the proclamation).

Scope expansion from the previous solar cells and modules safeguard tariff

Imports of silicon photovoltaic cells and modules under HTSUS 8541.42.00 and 8541.43.00 were previously subject to a safeguard action under Section 201 of the Trade Act of 1974, under which the United States had imposed tariff-rate quotas (TRQs) from January 2018 to February 2026. The Section 232 proclamation notes that the new action replaces the safeguard (as safeguard actions are limited to eight years), but that the scope is broader, reaching further upstream to cover polysilicon, ingots, and wafers.

Tariff and MIP levels

The two tariff measures imposed by the proclamation are:

1. A 15% ad valorem tariff on the covered polysilicon derivatives (ingots, wafers, cells, and modules).

There are two sets of country-specific modifications to this otherwise global tariff:

• For products of the United Kingdom, the tariff is 10%.
• For products of Japan, South Korea, Taiwan, Switzerland, Liechtenstein, and the European Union with Column 1 duty rates of less than 15%, the sum of the Section 232 tariff and the applicable Column 1 duty rate is capped at 15%.²

2. Minimum import prices on polysilicon and polysilicon derivatives. If the price of the product is not equal to or greater than the prescribed MIP level, a specific tariff up to the MIP level will apply to account for the price shortfall. If importers fail to submit the required pricing documentation, then the full amount of the MIP level will apply as a specific tariff. The specific tariff amount is additive ("stacks") with the 15% ad valorem tariff. The MIPs are:

• $21 per kilogram for polysilicon.
• $100 per kilogram for polysilicon ingots and wafers.
• $0.22 per watt for solar cells.
• $0.38 per watt for solar modules.

The proclamation states that Commerce may adjust the MIP levels "to reflect market conditions or other factors affecting the fair market value of covered products under non-distorted, free-market conditions."

Annex II to the proclamation implements these measures through new HTSUS Chapter 99 subheadings 9903.45.30 through 9903.45.36, covering the ad valorem and specific tariffs (including the country-specific modifications).

Calculating and applying the MIP specific tariff

To comply with the MIPs, importers will have to file documentation at entry with US Customs and Border Protection (CBP) demonstrating that (1) the product's entered value meets or exceeds the applicable MIP, and (2) that the imported product (or any downstream product made with the imported product) will be sold in the United States at a price at or above the applicable MIP. If the product is being resold in the United States "pursuant to fixed terms in a time-limited contract entered into prior to August 6, 2026," then the condition regarding domestic resale price level is waived.

The proclamation further instructs CBP to monitor the accuracy of importers' documentation. In addition to standard penalties for non-compliance with import rules, the proclamation states that, if "an importer's documentation was materially inaccurate or that an importer has materially failed to comply with its certification," then "that importer and its affiliates shall permanently be prohibited from importing polysilicon and polysilicon derivatives into the United States."

Limits on use of manufacturing drawback

The proclamation significantly limits the use of manufacturing drawback under 19 U.S.C. 1313(a)-(b). Manufacturing drawback will be available only with respect to the Section 232 tariffs if:

• The article is not a type of article that is subject to an antidumping or countervailing duty order (regardless of country of origin);
• The article is a product of the United Kingdom, the European Union, Japan, South Korea, Switzerland, Liechtenstein, Mexico, Canada, or "any trading partner with which the United States concludes a trade and security agreement" (which the proclamation does not define); and
• The polysilicon in the article is sourced from one of the countries above.

Currently, there are antidumping and countervailing duty orders in effect for certain solar cells and modules from various countries, excluding those products from qualifying for manufacturing drawback.

The polysilicon tariffs stack with all other applicable tariffs

The ad valorem and specific tariffs in the polysilicon Section 232 action stack with all other applicable tariffs (including antidumping and countervailing duties, the various other sector-specific Section 232 actions, and the Section 301 tariffs), to the extent the covered HTSUS codes overlap between the tariff orders. Annex II to the proclamation confirms that goods eligible for preferential treatment under a free trade agreement or preference program continue to owe the Section 232 duties in addition to their special program rate, and that all antidumping, countervailing, or other duties and charges continue to apply.

The Section 232 action's lack of tariff non-stacking provisions is notable, as the Trump administration has previously separated its sector-specific Section 232 tariff actions from its more general global "reciprocal" tariff policy imposed under the International Emergency Economic Powers Act (IEEPA), Section 122 of the Trade Act of 1974, and (currently) Section 301 of the Trade Act of 1974. It is unclear whether this was an oversight that will later be corrected or was intended. Currently, the solar cells and modules subject to the polysilicon Section 232 tariff are also subject to the 10%–12.5% "forced labor" Section 301 tariffs for the 60 economies covered by the "forced labor" Section 301 action, which will be additive. For products of China, all the products covered by the polysilicon Section 232 tariffs are also covered by the 2018 China Section 301 tariffs.

Tariff offsets for companies investing in US manufacturing

The proclamation includes a tariff offset mechanism under which Commerce may approve company-specific "onshoring plans" that would allow duty-free import of both production equipment and the covered polysilicon and polysilicon derivatives for companies committing to building, expanding, or refurbishing US polysilicon and polysilicon derivatives production facilities. The import volumes benefiting from the tariff offset would be based on what Commerce "deems commensurate with the company's newly committed investment." The proclamation also notes that the benefits may vary "depending on whether the imports use United States polysilicon."

Commerce will provide further guidance on implementing the offset mechanism and the application system. At the broad level described in the proclamation, the envisioned system resembles offset systems the Trump administration has recently introduced in the pharmaceutical and aluminum Section 232 tariff actions,³ suggesting the administration may be moving towards a standard approach to offering tariff exceptions in exchange for investment commitments.

Possibility of future mutual tariffs with partner countries

The proclamation raises the possibility that the Trump administration may waive the tariffs for specific countries, if those countries agree to adopt their own equivalent MIPs targeting imports from third countries. If a partner country has established a substantially equivalent MIP, Commerce and the United States Trade Representative (USTR) are directed to "alter the applicability of the MIP and the tariffs established in this proclamation to polysilicon and polysilicon derivatives from that trading partner." The proclamation provides no further details on how the negotiations should be conducted or what countries the Trump administration hopes to bring into the price floor arrangement.

The provision resembles the proposed plurilateral, tariff-enforced mutual price floors on critical minerals that USTR has proposed as part of the recently launched negotiations for a "Plurilateral Agreement on Trade in Critical Minerals."⁴ USTR has announced action plans for the negotiations with the European Union, Japan, and Mexico,⁵ but the negotiations appear to still be in their early phases.

_{1 Presidential proclamation of August 6, 2026: "Adjusting Imports of Polysilicon and its Derivatives into the United States," and Annex I (showing which products are under each MIP) and Annex II (containing the technical tariff amendments).
2 All products covered by the Section 232 tariff action are duty free under Column 1, making the inclusion of this provision redundant.
3 See, "Procedures To Apply for Company-Specific Onshoring Agreements To Obtain Tariff Adjustments for Pharmaceuticals and Pharmaceutical Ingredients Under Proclamation 11020," 91 FR 26989 (May 13, 2026); and Proclamation 11045 of July 20, 2026: "Further Strengthening Actions Taken To Adjust Imports of Aluminum Into the United States," 91 FR 46635 (July 23, 2026).
4 See, "USTR Seeks Public Comment on the Design of a Plurilateral Agreement on Trade in Critical Minerals and Policy Actions to Strengthen the Resilience of Critical Mineral Supply Chains," USTR, February 26, 2026. For additional analysis by White & Case, see the February 27, 2026, Client Alert, "Trump administration seeks public input for proposed critical minerals trade agreement;" and the January 16, 2026, Client Alert, "President Trump orders critical minerals trade negotiations in Section 232 action."
5 "Ambassador Jamieson Greer Announces U.S.-Mexico Action Plan on Critical Minerals," USTR, February 4, 2026; and "Ambassador Jamieson Greer Announces Critical Minerals Cooperation with the European Union and Japan," USTR, February 4, 2026.}

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