9903.94.05: Section 232 Auto Parts Tariff Rate, Scope, and Stacking

Key Points

• HTS 9903.94.05 imposes a 25 percent additional duty on automobile parts covered by U.S. note 33(g) to Chapter 99, effective from May 3, 2025, for the enumerated subheadings, with no announced end date for most lines.
• The 25 percent rate is an additional duty that stacks on top of the applicable Column 1 (MFN) rate for most trading partners, but for deal-country partners (such as the UK, Japan, the EU, and South Korea) the combined rate is the stated inclusive figure, not additive on top of MFN.
• Goods described in headings 9903.94.06, 9903.94.32, 9903.94.33, 9903.94.42, 9903.94.43, 9903.94.44, 9903.94.45, 9903.94.52, 9903.94.53, 9903.94.54, 9903.94.55, 9903.94.62, 9903.94.63, 9903.94.66, and 9903.94.67 are explicitly excluded from this heading.
• Coverage spans at least 135 specific HTSUS subheadings, ranging from rubber tires and tubes to spark-ignition engines, fuel pumps, air-conditioning units, and a wide range of other automotive components.
• Importers should verify each part-level subheading in the current HTSUS and confirm their specific country-of-origin rate treatment with a licensed broker, as the full list of 135 covered subheadings exceeds what is reproduced here.

On this page

1. What 9903.94.05 covers and what it excludes
2. The 25 percent rate and its effective window
3. Which HTSUS subheadings are in scope
4. How 9903.94.05 stacks with other duties
5. How this code appears on a CBP entry
6. What importers should do
7. Key references

HTS 9903.94.05 is a Chapter 99 provision that applies a 25 percent additional duty to automobile parts as defined in subdivision (g) of U.S. note 33 to Chapter 99, under the Section 232 national-security tariff program for autos and auto parts. As of October 1, 2026, the duty is in effect for the enumerated subheadings beginning May 3, 2025, with no announced end date for any of those lines. The links throughout this article go to the primary documents: the proclamations, Federal Register notices, and official tariff schedule pages themselves. Read the source.

What 9903.94.05 covers and what it excludes

The official heading text captures automobile parts as provided for in subdivision (g) of U.S. note 33 to Chapter 99, but only those parts that are not described in the following excluded headings:

• 9903.94.06
• 9903.94.32
• 9903.94.33
• 9903.94.42
• 9903.94.43
• 9903.94.44
• 9903.94.45
• 9903.94.52
• 9903.94.53
• 9903.94.54
• 9903.94.55
• 9903.94.62
• 9903.94.63
• 9903.94.66
• 9903.94.67

Those excluded headings carry their own country-specific or product-specific rate treatment under the Section 232 autos and parts framework. If your part falls within any of those headings, 9903.94.05 does not apply to that shipment. Confirm the correct heading with your broker and the current HTSUS at hts.usitc.gov before filing.

For background on the related Section 232 auto tariff that applies to finished automobiles and the companion parts provisions, see our article on 9903.94.01: Section 232 Auto Tariff Rate, Scope, and Stacking.

The 25 percent rate and its effective window

The duty under 9903.94.05 is 25 percent additional on the customs value of covered automobile parts. For the enumerated subheadings, the rate took effect on May 3, 2025, and no end date has been announced as of October 1, 2026.

The heading 8708 entry in the covered-goods list ran from May 3, 2025, through May 2, 2025, which reflects a one-day or zero-duration window in the facts for that broad heading. All remaining enumerated subheadings show a May 3, 2025, start with no announced end date. Confirm the current status of heading 8708 coverage in the HTSUS or with CBP before classifying broad 8708 goods under this provision.

Which HTSUS subheadings are in scope

The Section 232 auto parts list covers at least 135 subheadings. The following are among the covered lines, each effective from May 3, 2025, onward with no announced end date:

• 4009.12.0020, 4009.22.0020, 4009.32.0020, 4009.42.0020 (rubber hoses for automotive use)
• 4011.10.10, 4011.10.50, 4011.20.10 (new pneumatic tires for automobiles and buses/trucks)
• 4012.19.40, 4012.19.80, 4012.20.60 (retreaded and used tires)
• 4013.10.0010, 4013.10.0020 (inner tubes for automotive tires)
• 4016.99.6010 (rubber parts for motor vehicles)
• 7007.21.51 (laminated safety glass for vehicles)
• 7009.10.00 (rear-view mirrors)
• 7320.10, 7320.20.10 (leaf springs and coil springs of iron or steel)
• 8301.20.00 (padlocks and locks for motor vehicles)
• 8302.10.30 (hinges for motor vehicles)
• 8302.30 (other mountings and fittings for motor vehicles)
• 8407.31.00, 8407.32, 8407.33, 8407.34 (spark-ignition reciprocating engines)
• 8408.20.20 (compression-ignition engines for vehicles)
• 8409.91.1040, 8409.99.1040 (engine parts)
• 8413.30.10, 8413.30.90, 8413.91.10, 8413.91.9010 (fuel, lubricating, and cooling-medium pumps)
• 8414.30.8030, 8414.59.30, 8414.59.6540, 8414.80.05 (compressors and fans)
• 8415.20.00 (air-conditioning machines for motor vehicles)
• 8421.23.00 (oil or fuel filters for internal combustion engines)
• 8421.32.00 (intake air filters for engines)
• 8425.49.00 (other jacks and hoists)

This is a partial list. The full schedule contains 135 covered subheadings. Use the official HTSUS to verify your specific 10-digit classification before filing.

How 9903.94.05 stacks with other duties

Understanding rate stacking is critical to calculating your actual duty bill correctly.

Standard (MFN) country treatment

For goods imported from countries that do not have a negotiated deal arrangement under the Section 232 auto framework, the 25 percent additional duty under 9903.94.05 is additive on top of the applicable Column 1 (MFN) rate for the underlying Chapter 1-97 classification. Your total rate is: MFN rate + 25 percent.

Deal-country treatment (UK, Japan, EU, South Korea, and similar)

For goods from countries covered by a Section 232 auto-parts deal arrangement, the rate structure is different and critically important. The combined rate stated for those deal countries is an inclusive rate, not additive on top of MFN. Do not add MFN on top of the deal-country combined rate. The facts block for 9903.94.05 states the rate as 25 percent additional; confirm in the current HTSUS U.S. note 33 and the applicable deal-country headings (9903.94.32, 9903.94.33, 9903.94.42, 9903.94.43, 9903.94.44, 9903.94.45, 9903.94.52, 9903.94.53, 9903.94.54, 9903.94.55, 9903.94.62, 9903.94.63, 9903.94.66, and 9903.94.67) what the inclusive combined rate is for your specific origin country, since those headings exclude goods from 9903.94.05.

Other Section 301 and additional duties

Depending on the country of origin, Section 301 duties or other additional duties may also apply to the same goods. Check whether any Section 301 Chapter 99 provision covers your specific subheading and origin. Use our duty calculator to model the cumulative duty exposure across all applicable provisions. For a broader overview of current Chapter 99 codes, see the 2026 tariff code overview.

How this code appears on a CBP entry

9903.94.05 is a Chapter 99 overlay code. It does not replace the underlying Chapter 1-97 classification for your auto part. On an ACE entry, you will report two lines for the same article:

• Line 1: The standard Chapter 1-97 HTSUS subheading (for example, 8413.30.10 for a fuel pump), with the applicable MFN or preferential rate.
• Line 2: 9903.94.05, with a 25 percent additional duty rate applied to the same customs value.

Both lines are required. Omitting the Chapter 99 line is an underpayment. For guidance on identifying duty underpayments before CBP does, see How Do I Find Duty Underpayments Before CBP Does?

CBP guidance on entry requirements and CSMS messages related to Section 232 auto parts are published at cbp.gov. Monitor that site for updated instructions on ACE filing procedures for this provision.

What importers should do

• Confirm your 10-digit classification. Run every auto part through the full HTSUS to determine whether it appears in the 135 covered subheadings under U.S. note 33(g) and whether 9903.94.05 or one of the excluded deal-country headings applies.
• Determine your rate-stacking correctly. If your goods originate from a deal-country trading partner covered by one of the excluded headings (9903.94.32 through 9903.94.67), use the inclusive combined rate for that heading, not 9903.94.05 plus MFN. Confirm the exact inclusive rate in U.S. note 33 and the applicable excluded heading.
• File both lines on every entry. Report the Chapter 1-97 subheading and 9903.94.05 as a separate line in ACE. Review past entries filed after May 3, 2025, for omissions and assess whether prior disclosure or a post-summary correction is warranted.
• Watch for future modifications. The Section 232 auto parts framework is subject to ongoing rulemaking and deal-country negotiations. Monitor federalregister.gov and whitehouse.gov for proclamations or executive orders that modify covered subheadings, rates, or effective dates.

Key references

• HTSUS Chapter 99, hts.usitc.gov: Official harmonized tariff schedule, including U.S. note 33 and the full text of heading 9903.94.05 and related provisions.
• CBP.gov: U.S. Customs and Border Protection guidance, CSMS messages, and entry instructions for Section 232 auto parts.
• Federal Register, federalregister.gov: Federal Register notices implementing and modifying Section 232 auto and auto parts tariffs.
• White House, whitehouse.gov: Presidential proclamations and executive orders establishing and amending Section 232 auto tariff actions.
• 9903.94.01: Section 232 Auto Tariff Rate, Scope, and Stacking: CustomsGenius article on the companion provision covering finished automobiles.
• How Do I Find Duty Underpayments Before CBP Does?: Guidance on internal audit posture for Section 232 and other additional-duty provisions.