Executive summary

On 6 August 2026, President Donald Trump issued a proclamation, "Adjusting Imports of Polysilicon and Its Derivatives Into the United States," adjusting imports of polysilicon and its derivative products under Section 232 of the Trade Expansion Act of 1962 (Section 232). The action follows a report from the Secretary of Commerce (the Secretary) finding that imports of polysilicon and its derivatives are entering the United States in such quantities and under such circumstances as to threaten to impair the national security.

The proclamation combines two remedies: (1) a minimum import price (MIP) program and (2) a 15% ad valorem tariff on polysilicon derivatives, with a company-specific onshoring incentive program. The stated intent is to establish a commercially viable domestic market for the full range of polysilicon and polysilicon derivatives, including semiconductor and solar-grade material. The tariff replaces a narrower safeguard on solar cells and modules that expired in February 2026.

The polysilicon action complements the semiconductor Section 232 measures adopted in Proclamation 11002 of 14 January 2026, which the new proclamation cites in connection with scaling US semiconductor production. Covered products are identified in Annex I and Annex II to the proclamation.

Background

Section 232 authorizes the President to adjust imports of an article and its derivatives that are being imported in quantities, or under circumstances, that threaten to impair national security. Section 604 of the Trade Act of 1974 (19 U.S.C. 2483) authorizes the President to embody the substance of such actions in the Harmonized Tariff Schedule of the United States (HTSUS).

According to the proclamation, the Section 232 report, which the US Secretary of Commerce (the Secretary) delivered, determined that polysilicon is the base material for semiconductors and solar products and is essential to the national security and economy of the United States. The report also found that the US share of global polysilicon production capacity declined from 50% in 2005 to less than 2% in 2024, that global polysilicon production has grown by more than 270% since 2020, and that semiconductor-grade polysilicon now accounts for only 2.4% of global polysilicon production. Concurring with the Secretary's findings, the President determined that adjusting imports of polysilicon and its derivatives is necessary to safeguard national security.

Minimum import price program

Effective for goods entered for consumption, or withdrawn from a warehouse for consumption, on or after 12:01 a.m. Eastern Time on 4 December 2026, imports of polysilicon and polysilicon derivatives specified in Annexes I and II are subject to the MIP program. The applicable minimum import prices are:

The Secretary is authorized to adjust these minimum import prices from time to time to reflect market conditions or other factors affecting fair market value. Under the program:

• At entry, US Customs and Border Protection (CBP) will permit importers to submit documentation certifying either that any first arm's-length sale of the imported merchandise (or applicable downstream products) in the United States will occur at or above the applicable MIP, or that the first arm's-length sale is pursuant to fixed terms in a contract entered into before the date the proclamation was signed.
• If an importer submits the documentation but the entered value on the entry summary is less than the MIP, the merchandise is subject to a specific tariff equal to the difference between the entered value and the MIP.
• If an importer does not submit the required documentation, the merchandise is subject to a specific tariff equal to the applicable MIP.

CBP will monitor and enforce the accuracy of importer documentation. If CBP determines that documentation was materially inaccurate, or that an importer materially failed to comply with its certification, that importer and its affiliates are permanently prohibited from importing polysilicon and polysilicon derivatives, and CBP may impose penalties consistent with applicable law.

15% ad valorem tariff on polysilicon derivatives

Effective for entries on or after 12:01 a.m. Eastern Time on 4 December 2026, imports of polysilicon ingots and polysilicon derivatives specified in Annexes I and II are subject to an additional 15% ad valorem duty, except as otherwise specified. These duties apply in addition to any other duties, taxes, fees and charges, and continue in effect unless expressly reduced, modified or terminated. Country-specific treatment applies as follows:

• For products of Japan, Korea, Taiwan, Switzerland, Liechtenstein or member of the European Union, the sum of the additional Section 232 tariff and the applicable Column 1 HTSUS duty rate is equal to 15%.
• For products of the United Kingdom, the applicable rate under the derivative-tariff clause is 10%.

Onshoring incentive program

The Secretary is authorized to establish a program to encourage US investment in the production of raw polysilicon, as well as ingots, wafers and cells derived from polysilicon (Covered Products). Companies may submit onshoring plans that commit to build, refurbish or expand a US facility producing Covered Products, with construction starting by 20 January 2029. In evaluating plans, the Secretary will consider factors such as the anticipated construction start date, the commercial reasonableness of the project timeline and milestones, anticipated annual production, and cost and production projections.

For approved plans, the Secretary may allow the company to import necessary production equipment and Covered Products (in volumes the Secretary deems commensurate with the committed investment) without paying applicable Section 232 duties. These benefits are tied to the facility's construction period, are contingent on sufficient progress, and may vary depending on whether the imports use US polysilicon. Approved plans are subject to monitoring, reporting and potential external audit, and benefits may be rescinded retroactively in cases of fraud or deliberate misrepresentation.

Implementation and related measures

• Foreign Trade Zones (FTZs): Any product subject to duties under the proclamation, except those eligible for "domestic status" under 19 C.F.R. 146.43, that is admitted to a US FTZ on or after the effective date may be admitted only under "privileged foreign status" (19 C.F.R. 146.41).
• Drawback restrictions: Manufacturing drawback under 19 U.S.C. 1313(a)-(b) is available only for articles that (1) are not subject to an antidumping or countervailing duty order; (2) are products of Trade Agreement Partners (the United Kingdom, the European Union, Japan, the Republic of Korea, Switzerland, Liechtenstein, Mexico, Canada, and any partner concluding a trade and security agreement with the United States); and (3) have polysilicon content composed entirely of polysilicon from a Trade Agreement Partner country.
• Trade-deal partners: If a trading partner establishes a substantially equivalent MIP, the Secretary, in consultation with the US Trade Representative, may alter the applicability of the MIP and tariffs to that partner's polysilicon and derivatives.
• Anti-stockpiling and monitoring: The Secretary will continue to monitor imports and, if a company is found stockpiling ahead of the effective date, will coordinate with CBP to restrict imports by that company and its affiliates.
• HTSUS implementation: The Secretary, in consultation with the US International Trade Commission and CBP, will determine and publish a notice in the Federal Register providing necessary HTSUS modifications, including technical corrections to Annex I or Annex II.

What this means for businesses

The proclamation introduces a dual pricing-and-tariff mechanism that will require importers of polysilicon and its derivative ingots, wafers, solar cells and solar modules to assess exposure under both the MIP program and the 15% derivative tariff. Because duty outcomes turn on certified sale prices and documentation submitted at entry, companies should establish processes to substantiate first arm's-length sale prices or qualifying pre-signing contracts, and to maintain records supporting those certifications.

The certification regime represents heightened compliance obligations for importers, with potential consequences extending beyond monetary penalties to permanent loss of import privileges for Covered Products. Given the permanent import prohibition for material inaccuracies, documentation accuracy and internal controls are critical.

Country of origin will drive treatment under the 15% and 10% country-specific provisions and the drawback eligibility conditions, so origin determinations and content tracing for polysilicon inputs will be important. Companies weighing US investment should evaluate the onshoring program's duty-offset pathway against its construction-start and reporting commitments.

FTZ operators should confirm privileged foreign status admission, and all affected companies should monitor Federal Register notices and CBP guidance implementing the HTSUS changes.

Key dates

• 6 August 2026: Proclamation issued
• 4 December 2026: Effective date for the MIP program and the 15% derivative tariff
• 20 January 2029: Latest construction-start date for approved onshoring plans

Actions to consider

Businesses, depending on their circumstances, should consider the following actions:

• Identify import exposure across polysilicon and polysilicon-derivative ingots, wafers, solar cells and solar modules, and map products against Annexes I and II.
• Model landed-cost impact under both the MIP mechanism and the 15% ad valorem duty, including the country-specific 15% and 10% provisions.
• Establish entry documentation and certification processes to help substantiate first arm's-length sale at or above the applicable MIP or a qualifying pre-signing fixed-price contract.
• Validate country-of-origin determinations and trace polysilicon content to assess eligibility for manufacturing drawback and country-specific rates.
• Evaluate the onshoring incentive program and whether a Commerce Department-approved plan supports duty relief on equipment and Covered Products.