9903.05.37 El Salvador Section 301 Forced Labor: 10% Duty

Key Points

• HTS 9903.05.37 imposes an additional 10 percent ad valorem duty on all products of El Salvador across every chapter 1 through 97 classification, effective 2026-07-24 with no announced end date.
• The duty is authorized under the USTR Section 301 forced labor final action dated 2026-07-23 and is codified in U.S. note 52 of Chapter 99.
• The code covers all merchandise, regardless of product type, as long as it originates in El Salvador (country code SV).
• 9903.05.37 is a Chapter 99 overlay code; it must be reported on a separate line alongside the underlying chapter 1-97 classification on every affected entry.
• CBP implementation guidance was issued in CSMS 69326983; importers and brokers should review that message for ACE filing instructions.

On this page

1. What this code is and what triggered it
2. Products and country scope
3. The 10 percent rate and its effective window
4. How 9903.05.37 stacks with other duties
5. How this code appears on a customs entry
6. What importers should do
7. Key references

HTS 9903.05.37 is a Section 301 forced labor tariff code that adds 10 percent ad valorem to all products originating in El Salvador. It took effect on 2026-07-24 under authority of U.S. note 52 and the USTR Section 301 forced labor final action published 2026-07-23. Every importer bringing El Salvador-origin merchandise into the United States is affected as of that date.

The links throughout this article go to primary documents: USTR and CBP announcements, the official Harmonized Tariff Schedule, and the Federal Register. Read the source.

What this code is and what triggered it

Section 301 of the Trade Act of 1974 gives the USTR authority to investigate and respond to foreign trade practices that burden or restrict U.S. commerce. The forced labor variant of that authority, reflected in U.S. note 52 of Chapter 99, targets countries where forced labor practices in production have been identified as actionable. El Salvador is one of those countries.

The USTR issued its final action on 2026-07-23. CBP operationalized the duty the following day, 2026-07-24, and published filing guidance in CSMS 69326983. The country-specific codes for this program run from 9903.05.20 through 9903.05.84; 9903.05.37 is the heading assigned to El Salvador within that range.

Note that codes 9903.05.01 through 9903.05.09 belong to a separate Section 301 action involving Brazil and are not part of this forced labor program. Do not conflate the two.

Products and country scope

The scope of 9903.05.37 is deliberately broad. U.S. note 52(a) applies the additional duty to all chapter 1-97 products originating in El Salvador. There is no product-specific carveout or positive list. If a product:

• has a base classification anywhere in chapters 1 through 97 of the HTSUS, and
• originates in El Salvador (country code SV),

then 9903.05.37 applies. Confirm origin determination and applicable rules of origin with your broker or in the current HTSUS, because origin, not simply the country of export or shipment, controls eligibility.

For comparison, other countries in the same Section 301 forced labor program carry different rates. For example, the Ecuador action at 9903.05.35 also carries 10 percent, while the Dominican Republic at 9903.05.34 carries 12.5 percent. Rates are country-specific; do not assume one country's rate applies to another.

The 10 percent rate and its effective window

As of the facts available through 2026-09-04, the rate is 10 percent additional ad valorem, effective from 2026-07-24 onward with no announced end date. The duty is calculated on the entered value of the goods, the same basis used for most ad valorem duties.

Because no sunset or review date appears in the facts block, importers should treat this rate as open-ended until the USTR formally modifies or terminates the action. Monitor the Federal Register and CBP's CSMS feed for any amendments.

The facts block does not indicate an MFN cap for El Salvador at this code. If you have questions about whether a cap applies to specific merchandise, confirm in the current HTSUS or with a licensed broker.

How 9903.05.37 stacks with other duties

The 10 percent additional duty under 9903.05.37 is assessed on top of, not instead of, all other applicable duties. That means it stacks with:

• Column 1 (MFN/general) rates from the underlying chapter 1-97 classification.
• Any other Section 301 duties that may apply to the same goods based on product type or other country-of-origin findings.
• Antidumping and countervailing duties (AD/CVD), if an order covers the product.
• Section 232 duties on steel, aluminum, or other covered products, if applicable.

The total duty liability on a given shipment is the sum of all applicable rates. Use a duty calculator or consult your broker to model the combined impact before each entry. Our duty calculator can help you estimate stacked duty costs.

For a broader comparison of how Section 301 interacts with Section 232 and Section 201, see Section 232 vs 301 vs 201: Three Trade Remedy Tools Compared.

How this code appears on a customs entry

Chapter 99 overlay codes, including 9903.05.37, are reported on a separate line on the CBP Form 7501 and in ACE, directly below the underlying chapter 1-97 line item. The structure looks like this on each affected line:

• Line 1: the regular chapter 1-97 HTS classification (for example, a textile under chapter 62), with its standard duty rate.
• Line 2: 9903.05.37, with the entered value repeated and the 10 percent additional duty calculated on that value.

The entered value for the Chapter 99 line is the same as the entered value declared on the underlying classification line. Duty is computed separately on each line and then summed. CSMS 69326983 contains CBP's specific ACE filing instructions; review it before submitting entries that include El Salvador-origin merchandise. Errors in overlay-code reporting are a common source of CBP liquidation adjustments and CF-28 and CF-29 correspondence.

For a broader look at how 2026 tariff codes are being administered, see our 2026 tariff code overview.

What importers should do

• Audit open purchase orders and open entries. Identify all El Salvador-origin goods that entered on or after 2026-07-24. If 9903.05.37 was not reported on those entries, file a prior disclosure or post-summary correction as appropriate, and consult your broker on the correction mechanism available for your entry type.
• Update your ACE and ERP templates. Add 9903.05.37 as a mandatory overlay code for all El Salvador-origin lines on new entries. Verify that your broker's system has the code active, referencing CSMS 69326983 for the required data elements.
• Model total landed cost. Stack the 10 percent additional duty against column 1 rates, any applicable AD/CVD, and any other Section 301 or Section 232 duties for every El Salvador product category you import. Update your cost models and pricing agreements accordingly.
• Monitor for changes. Because no end date is announced, set calendar reminders to check the Federal Register and CBP CSMS for any modification or termination of the forced labor action covering El Salvador.

Key references

• Harmonized Tariff Schedule of the United States (hts.usitc.gov) - Official schedule including Chapter 99, U.S. note 52, and 9903.05.37.
• CBP CSMS 69326983 - CBP ACE filing guidance for the Section 301 forced labor action covering El Salvador.
• Federal Register (federalregister.gov) - Search for USTR Section 301 forced labor final action published 2026-07-23.
• U.S. Customs and Border Protection (cbp.gov) - CBP trade announcements, CSMS messages, and entry guidance.
• Office of the U.S. Trade Representative (ustr.gov) - USTR Section 301 forced labor program and final action documents.
• 9903.05.35 Ecuador Section 301 Forced Labor: 10% Duty - Related country-specific code in the same program.
• Section 232 vs 301 vs 201: Three Trade Remedy Tools Compared - Background on the legal authorities behind these duties.