9903.74.09 Explained: MHDV 232 Parts, Rate, Scope, and Stacking

Key Points

• HTS 9903.74.09 imposes an additional 25% duty on medium- and heavy-duty vehicle (MHDV) parts covered by nine Chapter 87 subheadings, effective April 3, 2025, with no announced end date.
• The rate is the duty provided in the applicable Chapter 1-97 subheading plus 25%, meaning the 25% stacks on top of whatever base rate already applies.
• The nine covered subheadings are 870410, 870422, 870423, 870432, 870442, 870443, 870452, 870460, and 870490, all as defined in subdivision (j) of U.S. Note 38 to Chapter 99.
• This is a Section 232 measure; the legal authority governing product scope and country applicability is U.S. Note 38 to the Chapter 99 subchapter of the HTSUS.
• Because no end date has been announced, importers should treat this surcharge as indefinite and factor it into landed-cost models for all current and prospective shipments.

On this page

1. What 9903.74.09 is and who must care
2. Product scope: the nine covered subheadings
3. The 25% rate and how it stacks
4. How 9903.74.09 appears on a customs entry
5. Interaction with other tariff provisions
6. What importers should do
7. Key references

HTS 9903.74.09 is a Chapter 99 overlay code that adds a 25% Section 232 duty to medium- and heavy-duty vehicle parts falling within nine specific Chapter 87 subheadings. It applies to goods entered on or after April 3, 2025, and no end date has been announced. Any importer, broker, or trade attorney handling MHDV parts must add this code to every qualifying entry or risk under-payment of duties.

The links in this article go to the primary documents: the official tariff schedule, CBP guidance pages, and government notice repositories themselves. Read the source.

As of October 9, 2026, the information below reflects the facts published in the Harmonized Tariff Schedule of the United States (HTSUS) for subheading 9903.74.09.

What 9903.74.09 is and who must care

9903.74.09 is one of several Chapter 99 codes created under the Section 232 medium- and heavy-duty vehicles (MHDV) program. The official heading text reads: "Medium- and heavy-duty vehicle parts, as provided for in subdivision (j) of U.S. note 38 to this subchapter." Subdivision (j) of U.S. Note 38 to the Chapter 99 subchapter is the controlling legal authority that defines exactly which goods fall under this code.

If you import goods classified under any of the nine Chapter 87 subheadings listed below, and those goods qualify as MHDV parts under subdivision (j) of U.S. Note 38, you are required to declare 9903.74.09 alongside your primary classification on every entry filed on or after April 3, 2025.

For context on how 9903.74.09 relates to companion MHDV codes covering complete vehicles and other parts categories, see our articles on 9903.74.08, 9903.74.02, and 9903.74.01.

Product scope: the nine covered subheadings

The HTSUS lists nine Chapter 87 subheadings whose parts may be subject to 9903.74.09, all effective April 3, 2025, with no announced end date:

• 870410 - Dumpers for off-highway use
• 870422 - Diesel-powered trucks of a GVW exceeding 5 metric tons but not exceeding 20 metric tons
• 870423 - Diesel-powered trucks of a GVW exceeding 20 metric tons
• 870432 - Other diesel-powered trucks of a GVW exceeding 5 metric tons
• 870442 - Other motor vehicles with spark-ignition engine of a GVW exceeding 5 metric tons
• 870443 - Other motor vehicles, other, of a GVW exceeding 5 metric tons but not exceeding 20 metric tons
• 870452 - Other motor vehicles, other, of a GVW exceeding 20 metric tons
• 870460 - Other motor vehicles, electric
• 870490 - Other motor vehicles, other

The subheading numbers above identify the vehicle type that the parts are designed or used for, not the tariff number under which the parts themselves are classified. Your parts will carry their own Chapter 87 (or other chapter) classification. The coverage question is whether those parts fall within subdivision (j) of U.S. Note 38 as parts for vehicles of these types. Confirm the exact scope of subdivision (j) in the current HTSUS or with your broker, as the note text governs.

The 25% rate and how it stacks

The HTSUS general-column rate for 9903.74.09 is: the duty provided in the applicable subheading + 25%.

This means the 25% is additive. It sits on top of the normal Most Favored Nation (MFN) column 1 general rate that applies to your specific parts subheading. If your parts already carry a 2.5% MFN rate, your total tariff exposure under 9903.74.09 is 27.5% of customs value. If they carry a 0% MFN rate, your exposure is 25%.

Stacking with other Section 301 or Section 232 measures

Whether the 25% MHDV Section 232 surcharge stacks with Section 301 duties or other Section 232 measures on the same goods depends on the specific country of origin and the product. The facts block for 9903.74.09 does not specify country exclusions, exemptions, or stacking rules with other programs. Confirm current stacking treatment in the HTSUS and with CBP guidance before filing. For a broader look at how multiple 232 codes interact on a single entry line, the article on 9903.82.06 rate, scope, and stacking illustrates the general mechanics, though its facts are specific to that code.

How 9903.74.09 appears on a customs entry

Chapter 99 codes are secondary codes. They do not replace your Chapter 1-97 classification; they ride alongside it on the same entry line. A correctly filed entry will show:

• Line 1, primary code: the Chapter 87 (or other chapter) subheading that classifies the part itself, with its applicable MFN rate
• Line 1, secondary code: 9903.74.09, with the additional 25% duty calculated on the same entered value

Both codes must appear on the entry for CBP to assess the correct total duty. Omitting 9903.74.09 on a qualifying entry creates a duty shortfall that CBP can pursue on liquidation or audit. If you have already filed entries since April 3, 2025 without this code and believe they should have included it, see the article on correcting HTS classification after entry for the available remedies.

For a technical overview of how tariff codes are organized across chapters in the current schedule, see the 2026 tariff code overview.

Interaction with other tariff provisions

Other MHDV 232 codes

The MHDV Section 232 program encompasses multiple Chapter 99 subheadings. 9903.74.09 specifically covers parts described in subdivision (j) of U.S. Note 38. Other subdivisions of that note cover complete vehicles and additional parts categories under different 9903.74.xx codes. Verify which subdivision applies to your specific goods before choosing a Chapter 99 code, as misassignment between sibling codes is a common classification error.

Free Trade Agreement rates

The facts block for 9903.74.09 does not identify any country-specific exemptions or FTA carve-outs. Do not assume that preferential FTA rates eliminate or offset the Section 232 surcharge. Confirm the current treatment for your country of origin in the HTSUS or with your licensed broker.

First Sale and assists

The 25% applies to the dutiable value declared on the entry. If you use first-sale valuation or have dutiable assists, ensure your value methodology is sound, because the Section 232 surcharge magnifies any valuation error. If you are exploring valuation strategies in a foreign trade zone context, the article on FTZ weekly entries covers mechanics that can affect when and how duty is calculated.

What importers should do

1. Audit your active parts classifications now. Cross-reference every Chapter 87 parts subheading you import against the nine subheadings listed above and the text of subdivision (j) of U.S. Note 38 in the HTSUS. If a parts line qualifies, 9903.74.09 must appear on every entry filed on or after April 3, 2025.
2. Review entries filed since April 3, 2025 for missing secondary codes. If qualifying entries were filed without 9903.74.09, determine whether a post-summary correction, protest, or prior disclosure is appropriate. The article on correcting HTS classification after entry explains each path and when to use it.
3. Update landed-cost models immediately. Because no end date has been announced, model the 25% surcharge as an indefinite cost. Any pricing, sourcing, or contract that was set before April 3, 2025 without accounting for this surcharge needs revision.
4. Verify stacking with other duties for each country of origin. Contact your broker or confirm in the current HTSUS and CBP guidance whether Section 301 or other Section 232 measures apply simultaneously to your specific goods and origin.

Key references

• Harmonized Tariff Schedule of the United States (HTSUS) - Official schedule including subheading 9903.74.09 and the full text of U.S. Note 38 to Chapter 99
• U.S. Customs and Border Protection (CBP) - Entry filing guidance, CSMS messages, and liquidation notices related to Section 232 MHDV duties
• Federal Register - Search for Section 232 MHDV notices and proclamations establishing the program
• White House Proclamations - Presidential proclamations implementing Section 232 MHDV measures
• 9903.74.08 Explained: MHDV 232 Parts, 25% Duty Rate and Scope - Companion MHDV parts code with parallel structure
• 9903.74.02 Explained: MHDV Section 232 Bus and Truck Tariff - Companion code covering complete vehicles
• Correct HTS Classification After Entry: PSC, Protest, or Prior Disclosure - Options for fixing entries that omitted 9903.74.09