9903.88.04 Explained: Section 301 China List 4, 25% Duty Rate

Key Points

• HTS 9903.88.04 imposes an additional 25% duty on articles that are the product of China and are enumerated in U.S. note 20(g) to Chapter 99 of the HTSUS.
• The total duty owed is the normal column-one rate of the underlying chapter 1-97 subheading plus 25%, applied on top of any other applicable duties.
• Thirteen specific carve-out headings (9903.88.33, .34, .36, .37, .38, .40, .46, .48, .56, .64, .66, .67, and .69) override 9903.88.04 for goods that fall within their scope.
• Coverage is determined by the product list in U.S. note 20(g); if a good's chapter 1-97 subheading does not appear there, 9903.88.04 does not apply.
• Facts in this article are as of October 10, 2026; confirm current scope and any exclusion orders directly in the HTSUS or with your broker.

On this page

1. What 9903.88.04 is and which program created it
2. Affected products and HTSUS coverage under U.S. note 20(g)
3. The 25% rate and how total duty is calculated
4. Carve-out headings that override 9903.88.04
5. How 9903.88.04 appears on a customs entry and stacks with other duties
6. What importers should do
7. Key references

HTS 9903.88.04 is a Section 301 Chapter 99 overlay code that adds 25% to the normal duty rate on qualifying Chinese-origin goods. It applies to every article that is the product of China and whose chapter 1-97 subheading is listed in U.S. note 20(g) to the HTSUS, unless one of thirteen named exception headings applies instead. Importers sourcing from China who classify goods under any subheading enumerated in note 20(g) must report this code on every entry and budget for the additional 25% on top of the column-one rate.

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

What 9903.88.04 is and which program created it

The Section 301 program targets goods that the U.S. Trade Representative determined benefit from China's unfair trade acts, policies, and practices. Under that program, the HTSUS was amended to add a series of Chapter 99 codes under heading 9903.88 that each correspond to a distinct product list and duty rate. The code 9903.88.04 is one of those overlay codes. It does not stand alone as a tariff classification; it always rides alongside a regular chapter 1-97 classification on the same entry line.

For background on related Section 301 codes covering other product lists and rates, see our articles on 9903.88.01 and 9903.88.02.

Affected products and HTSUS coverage under U.S. note 20(g)

The official heading text for 9903.88.04 reads: "Except as provided in headings 9903.88.33, 9903.88.34, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(g) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(g)."

Two conditions must both be true for a shipment to fall under 9903.88.04:

• Country of origin: The article must be the product of China. Country-of-origin rules for manufactured goods generally follow substantial transformation principles; confirm origin determinations with your broker or in CBP guidance.
• Subheading listed in U.S. note 20(g): The article's chapter 1-97 classification must appear on the enumerated list in U.S. note 20(g). Verify the current note text directly in the online HTSUS, because that list can be updated by regulatory action.

If either condition is not met, 9903.88.04 does not apply to the entry line.

The 25% rate and how total duty is calculated

The HTSUS general-column rate for 9903.88.04 is: the duty provided in the applicable subheading + 25%. In practice, the entry line will show both the chapter 1-97 subheading rate and the 9903.88.04 overlay. CBP's Automated Commercial Environment (ACE) system collects them together.

Simple calculation example

Suppose a product's chapter 1-97 subheading carries a 3.5% column-one rate and the product originates in China with a subheading listed in U.S. note 20(g). The effective rate on that entry line would be 3.5% plus 25%, for a combined 28.5% ad valorem duty. The 25% is calculated on the customs value, the same basis as the underlying rate.

Note that other overlay duties, such as antidumping or countervailing duties, may also stack on top. See the stacking section below.

Because tariff calculators pull from different snapshots of the schedule, verify your computed rate against the live HTSUS before filing. Our article Why Do Online Tariff Calculators Give Different Answers? explains why results can diverge.

Carve-out headings that override 9903.88.04

Thirteen Chapter 99 headings are expressly carved out of 9903.88.04's scope. When a good that would otherwise fall under 9903.88.04 also meets the criteria of one of these headings, the carve-out heading governs instead:

• 9903.88.33
• 9903.88.34
• 9903.88.36
• 9903.88.37
• 9903.88.38
• 9903.88.40
• 9903.88.46
• 9903.88.48
• 9903.88.56
• 9903.88.64
• 9903.88.66
• 9903.88.67
• 9903.88.69

Each of these carve-out codes has its own product scope, rate, and effective window. Importers whose goods may fit a carve-out heading should review each carve-out's U.S. note text and the associated subheading list in the HTSUS to determine which code is correct.

How 9903.88.04 appears on a customs entry and stacks with other duties

Chapter 99 co-classification

Chapter 99 codes are overlay codes: they do not replace the underlying chapter 1-97 classification. On a CBP entry, an affected line will carry both the regular subheading (for example, something in chapters 1-97) and 9903.88.04 as a secondary HTS number. ACE reads both codes and assesses the combined duty. Brokers must ensure both codes appear on the entry summary or CBP will not calculate the Section 301 component correctly.

Stacking with other Chapter 99 duties

Chinese-origin goods can simultaneously be subject to multiple Chapter 99 overlay codes, for example a Section 232 metals or vehicles tariff alongside the Section 301 code. Each overlay adds its own rate to the customs value. There is no automatic offset between them. Review all applicable Chapter 99 codes for every entry line involving Chinese-origin merchandise. For comparison, see how stacking works for another Chapter 99 overlay in our article on 9903.08.22 UAS 232 tariffs.

Antidumping and countervailing duties

Antidumping (ADD) and countervailing duties (CVD) are assessed separately from, and in addition to, the Section 301 duty. If a product is subject to an ADD or CVD order, all three components, the column-one rate, the 9903.88.04 25%, and the ADD/CVD rate, accumulate on the same entry line. Confirm open orders through the CBP and Department of Commerce databases.

First sale and assists

Because the 25% applies to the customs value, importers using first-sale valuation or reporting assists should ensure their valuation methodology is documented and defensible; a higher assessed value increases the dollar impact of the 25% rate proportionally.

What importers should do

• Verify coverage in U.S. note 20(g): Pull the current text of U.S. note 20(g) directly from hts.usitc.gov and confirm every chapter 1-97 subheading you import from China against that list before filing.
• Check all thirteen carve-out headings: For each affected subheading, review whether 9903.88.33, .34, .36, .37, .38, .40, .46, .48, .56, .64, .66, .67, or .69 applies, because reporting the wrong Chapter 99 code creates a duty discrepancy that CBP can flag on liquidation.
• Stack all applicable duties before entering: Calculate the column-one rate plus 25% plus any ADD/CVD or other Chapter 99 overlays to project the total landed duty cost and avoid surprises at liquidation.
• Monitor for list and rate changes: The Section 301 program has seen repeated amendments. Set up alerts for changes to U.S. note 20(g) and the carve-out headings; our article How Do I Get Tariff Change Alerts Only for Products I Import? explains how to do that efficiently.

Key references

• Harmonized Tariff Schedule of the United States (HTSUS), Chapter 99, heading 9903.88.04 and U.S. note 20(g), the authoritative source for the product list and rate.
• U.S. Customs and Border Protection (CBP), guidance on Section 301 entry procedures, ADD/CVD stacking, and CSMS messages.
• Federal Register, Section 301 rulemakings and product-list amendments affecting heading 9903.88 and its note structure.
• White House, presidential proclamations and executive orders related to the Section 301 tariff program.
• 2026 Tariff Code Overview, CustomsGenius reference page for Chapter 99 overlay codes effective in 2026.