9903.74.08 Explained: MHDV 232 Parts, 25% Duty Rate and Scope

Key Points

• HTS 9903.74.08 imposes a 25 percent additional duty on medium- and heavy-duty vehicle (MHDV) parts under the Section 232 national-security program, effective April 3, 2025, with no announced end date.
• Nine HTS subheadings under heading 8704 are covered: 870410, 870422, 870423, 870432, 870442, 870443, 870452, 870460, and 870490.
• The scope of covered goods is defined by subdivision (i) of U.S. note 38 to Chapter 99 of the HTSUS; importers must satisfy that note's product-scope language, not just the subheading number.
• The 25 percent additional duty stacks on top of the column 1 general rate and any other applicable Chapter 99 duties already due on the same line item.
• As of October 8, 2026, no end date has been announced, so the duty applies to all qualifying entries until further notice.

On this page

1. What 9903.74.08 covers and which program created it
2. Covered HTS subheadings and product scope
3. The 25 percent rate and its effective window
4. How 9903.74.08 stacks with other duties
5. How this code appears on a CBP entry
6. What importers should do
7. Key references

HTS 9903.74.08 is a Chapter 99 overlay code that adds a 25 percent Section 232 duty to medium- and heavy-duty vehicle parts falling under nine subheadings within HTS heading 8704, effective April 3, 2025. Any importer bringing in goods that match the product scope described in subdivision (i) of U.S. note 38 to Chapter 99 must report this code alongside the regular chapter 1-97 classification. The duty has no announced expiration date as of October 8, 2026.

The links throughout this article go directly to the primary documents: the official tariff schedule, CBP guidance pages, and government source materials themselves. Read the source before relying on any rate or scope determination for a live entry.

What 9903.74.08 covers and which program created it

The Section 232 medium- and heavy-duty vehicles (MHDV) program imposes additional duties on imports that the executive branch determined pose a national-security concern under the trade-expansion statute. Chapter 99 codes such as 9903.74.08 are the mechanism CBP uses to collect those duties at the border.

The official heading text for 9903.74.08 reads: "Medium- and heavy-duty vehicle parts, as provided for in subdivision (i) of U.S. note 38 to this subchapter." That cross-reference to U.S. note 38 is legally significant. The note, not the subheading alone, defines exactly which parts are in scope. Importers and brokers must read subdivision (i) of U.S. note 38 in the current Harmonized Tariff Schedule (hts.usitc.gov) to verify whether a specific product qualifies.

Covered HTS subheadings and product scope

As of October 8, 2026, nine subheadings under HTS heading 8704 (motor vehicles for the transport of goods) are subject to 9903.74.08, all effective April 3, 2025 with no announced end date:

• 8704.10 - Dumpers for off-highway use
• 8704.22 - Other, with compression-ignition internal combustion piston engine (diesel or semi-diesel), GVW exceeding 5 metric tons but not exceeding 20 metric tons
• 8704.23 - Other, with compression-ignition internal combustion piston engine (diesel or semi-diesel), GVW exceeding 20 metric tons
• 8704.32 - Other, with spark-ignition internal combustion piston engine, GVW exceeding 5 metric tons
• 8704.42 - Other, with electric motor for propulsion only, GVW exceeding 5 metric tons but not exceeding 20 metric tons
• 8704.43 - Other, with electric motor for propulsion only, GVW exceeding 20 metric tons
• 8704.52 - Other, plug-in hybrid, GVW exceeding 5 metric tons but not exceeding 20 metric tons
• 8704.60 - Other vehicles, not elsewhere specified
• 8704.90 - Other

Matching a subheading on this list is a necessary but not sufficient condition. The goods must also fall within the product description in subdivision (i) of U.S. note 38 to Chapter 99. Confirm that note in the current HTSUS or with your broker before filing.

If you are working with related auto and vehicle part classifications, see our articles on 9903.94.67 (Taiwan auto parts, 15% combined rate) and 9903.94.63 (South Korea auto parts, 15% combined rate) for comparison with other Section 232 vehicle programs.

The 25 percent rate and its effective window

The additional duty rate under 9903.74.08 is 25 percent of the customs value of the imported goods. This rate took effect on April 3, 2025 and has no published expiration or sunset date as of October 8, 2026. Because no end date has been announced, importers should treat this as an ongoing obligation until the HTSUS or an official proclamation states otherwise.

The 25 percent is an additional duty, meaning it is imposed on top of whatever column 1 general rate applies to the underlying chapter 1-97 subheading. It is not a replacement rate.

How 9903.74.08 stacks with other duties

Chapter 99 additional duties stack. When 9903.74.08 applies, the total duty obligation on an entry line is the sum of:

• The column 1 general rate for the base chapter 1-97 subheading (for example, from heading 8704);
• The 25 percent Section 232 MHDV additional duty under 9903.74.08; and
• Any other Chapter 99 additional duties that may also apply to the same goods (for example, Section 301 duties on goods of Chinese origin, or other Section 232 derivative-metals duties).

Stacking analysis is one of the most consequential steps in landing-cost modeling for MHDV parts. For context on how stacking works in related metal-content programs, see our articles on 9903.82.06 Consolidated Metal 232 and 9903.82.20 USMCA Derivative Steel 232.

Whether any exclusions, quota-based relief, or country-specific carve-outs reduce or eliminate the 9903.74.08 duty is governed entirely by U.S. note 38 and any subsequent proclamations or Federal Register notices. The facts block for this article does not identify country-specific exceptions; confirm the current state of the note at hts.usitc.gov or with your broker.

How this code appears on a CBP entry

9903.74.08 is a Chapter 99 overlay code. It does not replace the base classification; it rides alongside it. A properly filed entry will carry two HTS lines for the same physical goods:

• Line 1: The chapter 1-97 subheading (for example, 8704.23.XX) at its normal column 1 rate.
• Line 2: 9903.74.08 at 25 percent additional duty, referencing the same entered value.

Omitting the Chapter 99 line on a qualifying entry creates an underpayment of duties. CBP may issue a bill with interest, or the issue may surface during a compliance review. If you discover a misclassification or omission after entry, review your options in our article on correcting HTS classification after entry: PSC, protest, or prior disclosure.

For a broader orientation to Chapter 99 coding in the current tariff schedule, see the 2026 tariff code overview.

What importers should do

• Verify U.S. note 38, subdivision (i) in the live HTSUS. Pull the current version at hts.usitc.gov and confirm your specific MHDV parts fall within the note's product-scope language, not just the heading 8704 subheading.
• Model the full stacked duty rate. Add the 25 percent Section 232 MHDV duty to your column 1 rate and any other applicable Chapter 99 duties before calculating landed cost. Do not quote a single-rate figure to finance or procurement without the stacked total.
• Audit recent entries filed since April 3, 2025. If entries for heading 8704 goods were filed without 9903.74.08, assess whether a post-summary correction or prior disclosure is appropriate. See Correct HTS Classification After Entry for the procedural options.
• Monitor the HTSUS and Federal Register for changes. No end date has been announced as of October 8, 2026, but Section 232 programs have been modified by proclamation in the past. Set up a monitoring workflow for updates to U.S. note 38 and any related Federal Register notices.

Key references

• Harmonized Tariff Schedule of the United States (hts.usitc.gov) - The authoritative source for 9903.74.08, U.S. note 38, and all covered subheadings under heading 8704.
• U.S. Customs and Border Protection (cbp.gov) - CBP guidance, CSMS messages, and entry processing instructions for Section 232 duties.
• Federal Register (federalregister.gov) - Official notices and proclamations establishing and modifying the Section 232 MHDV program.
• White House proclamations (whitehouse.gov) - Executive proclamations issued under the Section 232 national-security authority that govern this program.
• Correct HTS Classification After Entry: PSC, Protest, or Prior Disclosure - Procedural options when 9903.74.08 was omitted from a filed entry.
• 9903.94.67 Explained: Taiwan Auto Parts 232 Combined 15% Rate - Related Section 232 vehicle program for comparison.