9903.45.31 Section 201 QSP Safeguard: Rate, Scope, and Stacking

Key Points

• HTS 9903.45.31 imposes a 50 percent additional duty on qualifying quartz surface products (QSPs) entered on or after 2026-08-15, under the Section 201 QSP Safeguard established by Proclamation 11051.
• The duty steps down each year: 50 percent (2026-08-15 through 2027-08-14), 49 percent (2027-08-15 through 2028-08-14), 48 percent (2028-08-15 through 2029-08-14), and 47 percent (2029-08-15 through 2030-08-14), with the program terminating on 2030-08-14.
• The code applies to goods classified under HTS subheadings 6810.99.0020, 6810.99.0040, and 7020.00.6000, but only when the product is a QSP as defined in U.S. note 41(a) and the country of origin is not exempt under U.S. note 41(c).
• A long list of countries is exempt from this code, including Canada, Mexico, Australia, South Korea, Israel, Singapore, and many developing nations. Shipments from non-exempt countries and above the quota quantity trigger 9903.45.31.
• Quota administration is governed by QB 26-601 and CBP CSMS message 69509193. Confirm in-quota versus over-quota status before filing your entry.

On this page

1. What 9903.45.31 is and who must care
2. Product scope: what qualifies as a QSP
3. HTS classification lines covered
4. Country exclusions under U.S. note 41(c)
5. Rate schedule and effective windows
6. Quota mechanics and how the code appears on an entry
7. Stacking with other duties
8. What importers should do
9. Key references

HTS 9903.45.31 is a Chapter 99 safeguard heading that adds a 50 percent duty, effective 2026-08-15, on quartz surface products imported from countries that are not exempt under U.S. note 41(c) to subchapter III of Chapter 99, when entered in quantities exceeding the quota defined in U.S. note 41(d). The duty was created by Proclamation 11051, published at 91 FR 50645, and applies through 2030-08-14 on a declining annual schedule. Every importer sourcing engineered stone countertops, slabs, or similar quartz-based fabricated surfaces from a non-exempt origin needs to account for this additional charge immediately.

The links in this article go to the primary documents: the proclamations, Federal Register notices, and official tariff schedule pages themselves. Read the source.

What 9903.45.31 is and who must care

As of 2026-08-26, this code is newly effective. It was added to the Harmonized Tariff Schedule of the United States (HTSUS) under the Section 201 global safeguard authority. Section 201 of the Trade Act of 1974 allows the President to impose temporary import relief when a domestic industry is seriously injured by increased imports. Proclamation 11051, appearing in the Federal Register at 91 FR 50645, is the controlling legal instrument. U.S. note 41 to subchapter III of Chapter 99 of the HTSUS contains the product definition (note 41(a)), the country exclusions (note 41(c)), and the quota trigger quantities (note 41(d)).

Importers of engineered stone or quartz-composite surfaces, their customs brokers, and trade counsel all need to evaluate every shipment against this code starting with entries filed on or after 2026-08-15. Retroactive entries do not apply; entries before that date are unaffected.

Product scope: what qualifies as a QSP

U.S. note 41(a) defines a quartz surface product using a two-part conjunctive test drawn directly from Proclamation 11051, paragraph 8:

• Composition: Silica must be the predominant material by actual weight, and the product must include a resin binder.
• Exclusion: Quarried natural stone is specifically excluded, regardless of silica content.

Both conditions must be satisfied for the heading to apply. An article that is predominantly silica by weight but uses no resin binder, or that is quarried natural stone, does not meet the QSP definition and should not carry 9903.45.31. For the dedicated HTS slab lines (6810.99.0020 and 6810.99.0040), these products are treated as QSP candidates by default given their specific product descriptions. For the broader residual glass line (7020.00.6000), QSP qualification must be established for each shipment. If you are uncertain whether your specific product meets the note 41(a) definition, confirm with a licensed customs broker or by reviewing the note text directly in the official HTSUS.

HTS classification lines covered

9903.45.31 rides alongside three underlying Chapter 1-97 subheadings. A correct entry will show both the chapter 1-97 classification and 9903.45.31 as a secondary line:

• 6810.99.0020: Articles of artificial stone, slabs, not elsewhere specified or included (dedicated QSP slab line).
• 6810.99.0040: Articles of artificial stone, other (dedicated QSP slab line).
• 7020.00.6000: Other articles of glass, not elsewhere specified or included (broader residual line; QSP qualification must be established for each entry).

If your goods are classifiable under 6810.99.0020 or 6810.99.0040, the QSP charge applies by default when origin and quota conditions are met. The 7020.00.6000 line requires an affirmative determination that the article meets the note 41(a) definition. Verify your classification on the HTSUS online schedule and confirm with your broker.

Country exclusions under U.S. note 41(c)

U.S. note 41(c) exempts a significant number of countries from 9903.45.31. Goods originating in any exempt country do not owe this additional duty regardless of quantity. The exempted countries as of 2026-08-26 include:

• Free Trade Agreement partners: Canada (CA), Mexico (MX), Australia (AU), Colombia (CO), Costa Rica (CR), Dominican Republic (DO), El Salvador (SV), Guatemala (GT), Honduras (HN), Israel (IL), Nicaragua (NI), Panama (PA), Peru (PE), Singapore (SG), South Korea (KR).
• Developing and beneficiary countries: Afghanistan, Albania, Algeria, Angola, Armenia, Azerbaijan, Belize, Benin, Bhutan, Bolivia, Bosnia and Herzegovina, Botswana, Brazil, Burkina Faso, Myanmar, Burundi, Cambodia, Cameroon, Cape Verde, Central African Republic, Chad, Comoros, Republic of Congo, Democratic Republic of Congo, Cote d'Ivoire, Djibouti, Dominica, Ecuador, Egypt, Eritrea, Eswatini, Ethiopia, Fiji, Gabon, Gambia, Georgia, Ghana, Grenada, Guinea, Guinea-Bissau, Guyana, Haiti, Indonesia, Iraq, Jamaica, Jordan, Kazakhstan, Kenya, Kiribati, Kosovo, Kyrgyzstan, Lebanon, Lesotho, Liberia, Madagascar, Malawi, Maldives, Mali, Mauritania, Mauritius, Moldova, Mongolia, Montenegro, Mozambique, Namibia, Nepal, Niger, Nigeria, North Macedonia, Pakistan, Papua New Guinea, Paraguay, Philippines, Rwanda, Saint Lucia, Saint Vincent and the Grenadines, Samoa, Sao Tome and Principe, Senegal, Serbia, Sierra Leone, Solomon Islands, Somalia, South Africa, South Sudan, Sri Lanka, Suriname, Tanzania, Timor-Leste, Togo, Tonga, Tunisia, Tuvalu, Uganda, Ukraine, Uzbekistan, Vanuatu, Yemen, Zambia, Zimbabwe.
• Caribbean and other territories: Antigua and Barbuda, Aruba, Bahamas, Barbados, British Virgin Islands, Curacao, Montserrat, Saint Kitts and Nevis, Trinidad and Tobago.

The exemption is self-executing: no claim or certificate is required on the entry beyond accurate country-of-origin declaration. If your origin is not on this list, your goods are subject to 9903.45.31 when they also exceed the quota quantity in note 41(d). For guidance on accurate origin declarations, see our article on country of origin marking requirements. If you source from third-country processing hubs, review substantial transformation rules before assuming a country of origin.

Importers should be aware that transshipment through an exempt country does not confer exempt status. CBP scrutinizes origin claims on products subject to safeguard duties. See our article on transshipment customs fraud for context on enforcement risks.

Rate schedule and effective windows

The duty under 9903.45.31 is an additional duty, layered on top of the normal column 1 rate for the underlying subheading. The rate declines annually over the program's four-year life:

• 50 percent additional duty: 2026-08-15 through 2027-08-14
• 49 percent additional duty: 2027-08-15 through 2028-08-14
• 48 percent additional duty: 2028-08-15 through 2029-08-14
• 47 percent additional duty: 2029-08-15 through 2030-08-14

The program is announced to terminate on 2030-08-14. No rate or extension beyond that date is established in the facts available as of 2026-08-26. The date of entry, not the date of export or purchase, determines which rate window applies. Use our duty calculator to model your landed cost under each window.

Quota mechanics and how the code appears on an entry

9903.45.31 applies only to entries that exceed the aggregate quantity threshold defined in U.S. note 41(d). Goods entered within that threshold quantity use a different Chapter 99 provision; 9903.45.31 is the over-quota heading. The quota is administered under Quota Bulletin QB 26-601, and CBP's operational instructions are in CSMS message 69509193, available via cbp.gov. Check both documents for current in-quota versus over-quota procedures, filing deadlines, and any first-come-first-served queue rules before filing.

On a CBP entry summary, 9903.45.31 appears as a second HTS line beneath the primary chapter 1-97 classification (e.g. 6810.99.0020). The 50 percent additional duty is assessed on the customs value of the over-quota portion. ACE will reject entries that do not include both lines when the over-quota condition applies. Confirm the entry format with your broker and cross-reference CBP's guidance in CSMS 69509193.

Stacking with other duties

The 50 percent (or subsequently stepped-down) rate under 9903.45.31 is an additional duty. It stacks on top of:

• The normal column 1 (MFN) rate for the underlying subheading (6810.99.0020, 6810.99.0040, or 7020.00.6000).
• Any applicable antidumping or countervailing duty orders covering the same goods and origin, if such orders exist. Confirm whether any ADD/CVD orders cover your specific product and supplier with your broker or by searching the CBP and Commerce databases, as the facts block is silent on this point.
• Other Section 301 or Section 232 additional duties, if the underlying subheading and origin are also subject to those programs. The facts block does not identify any such overlap, so confirm in the current HTSUS or with your broker.

The interaction of multiple Chapter 99 codes on a single entry line can produce a very high effective duty rate. Model your total landed cost carefully before each purchase order. For a broader overview of how Chapter 99 codes interact, see our 2026 tariff code overview.

What importers should do

• Confirm product qualification. Verify that your goods meet the U.S. note 41(a) two-part QSP definition (silica predominant by actual weight plus resin binder; quarried stone excluded) before applying 9903.45.31. For 7020.00.6000 entries in particular, document the qualification analysis in your entry records.
• Check country of origin and exemption status. Confirm the actual country of origin against the U.S. note 41(c) exemption list. If your supply chain involves third-country processing, apply a substantial transformation analysis before declaring an exempt origin.
• Monitor quota status before filing. Review QB 26-601 and CSMS 69509193 on cbp.gov to determine whether the in-quota quantity has been exhausted for the relevant period before filing under 9903.45.31 versus the in-quota provision.
• Update landed cost models for all four rate windows. Budget for the 50 percent rate through 2027-08-14, then update purchase order pricing to reflect the 49, 48, and 47 percent steps in subsequent years through program termination on 2030-08-14.

Key references

• 91 FR 50645: Federal Register publication of Proclamation 11051 establishing the Section 201 QSP Safeguard.
• HTSUS online schedule (hts.usitc.gov): U.S. note 41 to subchapter III of Chapter 99, including the QSP definition (note 41(a)), country exclusions (note 41(c)), and quota quantities (note 41(d)); also subheadings 6810.99.0020, 6810.99.0040, 7020.00.6000, and 9903.45.31.
• CBP.gov: CSMS 69509193 (operational instructions for 9903.45.31 entries) and Quota Bulletin QB 26-601 (quota administration).
• White House (whitehouse.gov): Proclamation 11051, the executive action authorizing the Section 201 QSP Safeguard.