Polysilicon Section 232 Tariff: 15% Duty + Price Floors Effective Dec 4, 2026

On August 6, 2026, the President signed a Section 232 proclamation, Adjusting Imports of Polysilicon and its Derivatives into the United States, imposing a 15% ad valorem additional duty on imported polysilicon ingots and polysilicon derivatives covered by Annexes I and II of the proclamation. The same proclamation establishes minimum import prices for the covered products, effective the same day: December 4, 2026, 12:01 a.m. Eastern, for goods entered for consumption or withdrawn from warehouse on or after that time.

Key dates

Tariff rate and minimum import price floors

The 15% ad valorem duty applies to polysilicon ingots and polysilicon derivatives in Annexes I and II. Importers must also comply with the new minimum import price program:

For entries on or after December 4, 2026, importers must certify that the first arm's-length sale in the U.S. is at or above the applicable MIP, or demonstrate that the goods are subject to fixed contract terms signed before the proclamation. If no documentation is provided, a specific tariff equal to the applicable MIP applies. If the entered value is below the MIP, the specific tariff equals the difference. Customs and Border Protection (CBP) will monitor documentation accuracy — materially inaccurate documentation or failed certification can trigger a permanent import ban plus penalties.

Country carve-outs

• Japan, South Korea, Taiwan, Switzerland, Liechtenstein, and EU member states: Section 232 duty plus Column 1 duty is capped at 15% total.
• United Kingdom: a 10% additional duty applies.
• All other countries: the full 15% Section 232 duty applies.

What importers should do now

The effective date is four months out, but documentation requirements start at the border on day one. Review your polysilicon and solar supply contracts now: identify which Annexes I and II products you import, confirm whether your purchase contracts were fixed before August 6, 2026, and build the MIP certification into your entry documentation process before December 4.

Related guides: Section 301 tariff expansion — 60 countries covered · Tariff impact on U.S. manufacturing supply chains · Tariffs on electronics imports from Asia