President Trump signed a proclamation on Aug. 6 imposing a new Section 232 tariff and a minimum import price (MIP) program on polysilicon and its derivatives, the base material used in semiconductors and solar products. The action follows a Commerce Department investigation into whether the United States’ shrinking domestic polysilicon capacity poses a national security risk.
What’s Changing, and When
Effective 12:01 a.m. ET on Dec. 4, 2026, for goods entered for consumption or withdrawn from warehouse for consumption on or after that date, imports of polysilicon ingots and the derivative products listed in Annex I and Annex II of the proclamation will be subject to an additional 15% ad valorem duty, except where the proclamation specifies otherwise.
The same effective date and time apply to a new set of minimum import prices. Importers will not be permitted to enter covered merchandise below these floors:
| Product | Minimum Import Price |
| Polysilicon | $21 per kilogram |
| Polysilicon ingots and wafers | $100 per kilogram |
| Solar cells | $0.22 per watt |
| Solar modules | $0.38 per watt |
Why the Administration Is Acting
Polysilicon underpins both the semiconductor and solar supply chains, and the administration frames this action as a national security measure. According to the Commerce Department, the U.S. share of global polysilicon production capacity has fallen from 50% in 2005 to less than 2% in 2024. U.S. semiconductor wafer fabrication capacity has fallen from 37% in 1990 to 10% in 2024, and the U.S. solar sector is now almost entirely dependent on imported ingots, wafers, and cells.
The proclamation also directs the Secretary of Commerce to establish an incentive program for companies investing in new, expanded, or refurbished U.S. polysilicon and derivative-product facilities, and leaves the door open for the U.S. Trade Representative to adjust the MIP and tariffs for trading-partner countries that adopt a substantially equivalent import-adjusting program of their own.
This is the latest in a string of Section 232 actions targeting the domestic tech and energy manufacturing base, following the January 14, 2026 proclamation adjusting imports of semiconductors, semiconductor manufacturing equipment, and their derivative products.
What Importers Should Do Now
- Identify whether any HTS numbers in your import portfolio fall within Annex I or Annex II once the annexes are published in the Federal Register.
- Build the Dec. 4, 2026 effective date into entry-filing and landed-cost planning; the additional 15% duty and the MIP floors apply to the entry date, not the contract or shipment date.
- Review supplier pricing against the new MIP thresholds well before December, since entries priced below the floor will not be permitted regardless of the commercial invoice value.
- Watch for CBP implementing guidance; NCBFAA’s Customs Committee and Sandler, Travis & Rosenberg, P.A. are monitoring the docket and will issue updates as CBP publishes them.
- Talk to your customs broker about classification and country-of-origin exposure now, particularly for downstream solar and semiconductor components that may be swept into the derivative annexes.
Have Questions About How This Affects Your Imports?
Alba’s trade compliance team can help you assess your exposure under the new polysilicon tariff and MIP program. Contact ASK Alba™ to talk through classification, entry timing, and supplier documentation ahead of the December effective date.
References
NCBFAA Customs Committee and Sandler, Travis & Rosenberg, P.A. member alert, Aug. 6, 2026
