4016.93.50 and Section 338 Canada: Rates, Scope, and Stacking

Key Points

• HTS 4016.93.50 ("Other" rubber articles under heading 4016) carries a general MFN rate of 2.5 percent; imports qualifying under listed FTAs and preference programs enter free of duty.
• Canada-origin entries presenting on or after 2026-08-19 are subject to the Section 338 overlay, which adds a Chapter 99 code on top of the 2.5 percent MFN rate; the exact additional rate for that overlay must be confirmed in the current HTSUS because the facts block does not assign a specific Section 338 rate to this classification.
• Four Chapter 99 codes are cross-referenced to this classification in the live schedule as of 2026-08-11: 9903.05.05, 9903.96.01, 9903.96.02, and 9903.90.08; each rides as a separate line element on the entry alongside 4016.93.50.
• 9903.90.08 carries 35 percent additional duty with no dates recorded in the facts block; confirm its current applicability to your shipment before entry.
• Column 2 countries face a 25 percent rate on this classification, entirely separate from MFN or Section 338 treatment.

On this page

1. What HTS 4016.93.50 covers
2. Base MFN rate and FTA preference rates
3. Section 338 Canada overlay: scope and effective date
4. All Chapter 99 overlays cross-referenced to this classification
5. How stacking works on the entry
6. What importers should do
7. Key references

HTS 4016.93.50 is a residual ("Other") classification within Chapter 40, heading 4016, covering certain articles of vulcanized rubber not elsewhere specified. As of 2026-08-11, the general MFN rate is 2.5 percent. Canada-origin goods entered on or after 2026-08-19 fall within the Section 338 Canada program and must carry the applicable Chapter 99 overlay code on each entry line. The links in this article go to the primary documents: the proclamations, Federal Register notices, and official tariff schedule pages themselves. Read the source.

What HTS 4016.93.50 covers

Heading 4016 of Chapter 40 covers articles of vulcanized rubber other than hard rubber. Subheading 4016.93.50 is the "Other" basket within that heading, capturing rubber articles that do not fit a more specific eight- or ten-digit provision in the same heading. Because it is a residual provision, the classification question is often whether the good belongs in a more specific subheading first. Confirm the classification against the current schedule at hts.usitc.gov and, if needed, with a licensed customs broker.

For a broader look at how 2026 tariff codes are structured, see the 2026 tariff code overview.

Base MFN rate and FTA preference rates

The general (Column 1 / MFN) duty rate for 4016.93.50 is 2.5 percent ad valorem. This rate applies to goods from all World Trade Organization member countries that do not qualify for a lower special rate and are not subject to Column 2 treatment.

Special (FTA and preference) rates

The following countries and programs are eligible for a Free rate under the special rate column for this classification:

• A* (Generalized System of Preferences, with asterisk indicating possible product or country limitations)
• AU (Australia)
• BH (Bahrain)
• C (NAFTA successor, as applicable)
• CL (Chile)
• CO (Colombia)
• D (African Growth and Opportunity Act)
• E (Caribbean Basin Initiative)
• IL (Israel)
• JO (Jordan)
• JP (Japan)
• KR (Korea)
• MA (Morocco)
• OM (Oman)
• P (Panama, as applicable)
• PA (Panama)
• PE (Peru)
• S (various preference programs)
• SG (Singapore)

Importers claiming a special rate must ensure that origin documentation (certificate of origin or equivalent) is in place and that the goods genuinely meet the applicable rules of origin. Confirm which indicator applies to your specific program in the current HTSUS.

Column 2 rate

Goods from countries subject to Column 2 treatment face a rate of 25 percent for this classification. Column 2 countries are not eligible for MFN or special rates.

Section 338 Canada overlay: scope and effective date

Section 338 is a U.S. trade action targeting imports of Canadian origin. For entries presenting on or after 2026-08-19, Canada-origin goods classified under 4016.93.50 are subject to the Section 338 overlay. The program is administered through Chapter 99 subheadings in the 9903.03.12 through 9903.03.16 range.

The facts block does not assign a specific additional duty rate for the Section 338 Canada overlay to this particular classification. Confirm the exact rate and the applicable 9903.03.xx code in the current HTSUS at hts.usitc.gov or with your customs broker before filing the entry.

Note: subheadings 9903.03.01 through 9903.03.11 belong to a superseded Section 122 block that is no longer live. Do not apply those codes to current Canada-origin entries.

For a practical look at how Section 338 stacks across other rubber and plastic classifications, see 3926.40.00 and Section 338 Canada: Rates, Scope, and Stacking.

All Chapter 99 overlays cross-referenced to this classification

As of 2026-08-11, four Chapter 99 codes appear in the live schedule alongside 4016.93.50. Each is a separate potential duty obligation depending on the nature and origin of the shipment.

9903.05.05: Section 301 Brazil Exemptions

Effective 2026-07-22 with no announced end date, this code provides that the duty is the duty provided in the applicable subheading. In practical terms, it is an exemption mechanism tied to Section 301 Brazil actions. Whether your specific goods qualify for this exemption must be verified against the current program criteria.

9903.96.01: Civil Aircraft Exemption

This code provides 0 percent additional duty and is effective from 2025-06-30 onward with no announced end date. It applies to qualifying civil aircraft parts and components. Applicability depends on whether the goods meet the civil aircraft program criteria.

9903.96.02: Civil Aircraft Exemption

Also providing 0 percent additional duty, this code is effective from 2025-09-16 onward with no announced end date. Like 9903.96.01, it is tied to civil aircraft eligibility criteria. Confirm which code applies to your goods, as the two codes have different effective start dates.

9903.90.08: 35 Percent Additional

This overlay carries a 35 percent additional duty. No effective dates are recorded in the facts block for this code. Because no date window is specified, you must confirm its current status and applicability to your specific shipment in the current HTSUS or with CBP guidance at cbp.gov before filing.

How stacking works on the entry

Chapter 99 overlay codes do not replace the Chapter 1-97 classification. Each applicable Chapter 99 code is reported as its own line element on the entry alongside 4016.93.50. The additional duties from the Chapter 99 codes are separate from and on top of the MFN rate (or special rate, if applicable).

For example, if the MFN rate of 2.5 percent applies and 9903.90.08 (35 percent additional) is also applicable, the total duty exposure is the sum of both. If a free special rate applies on the 4016.93.50 line but a Chapter 99 overlay adds additional duties, those additional duties still apply unless the overlay itself contains a carve-out.

Use the duty calculator to model combined duty exposure before your goods arrive. For the mechanics of customs valuation that feed into the duty calculation, see Customs Transaction Value: The Default Valuation Method Explained.

For a parallel example of Section 338 stacking on another classification, see 4823.90.86 and Section 338 Canada: Rates, Scope, and Stacking.

What importers should do

• Verify the exact Section 338 Chapter 99 subheading (9903.03.12 through 9903.03.16 range) and its additional rate for your specific goods in the current HTSUS at hts.usitc.gov before filing any Canada-origin entry on or after 2026-08-19.
• Confirm whether 9903.90.08 (35 percent additional, no dates recorded) is currently active and applicable to your shipment by checking the live HTSUS and any CBP guidance at cbp.gov.
• Ensure all Chapter 99 overlay codes that apply are reported as separate line elements on each entry, and that origin documentation is complete for any FTA or preference program claim on the 4016.93.50 line.
• Build a review step into your entry audit process to catch missed or incorrectly applied overlays; see Post Entry Audit Program: Build a Monthly Self-Review That Catches Errors for a practical framework.

Key references

• Harmonized Tariff Schedule of the United States (USITC): official current text of 4016.93.50 and all Chapter 99 overlays
• U.S. Customs and Border Protection: entry guidance, CSMS messages, and program-specific instructions
• Federal Register: Section 338 and Section 301 program notices and amendments
• White House: proclamations and executive orders underlying Section 338 and related trade actions
• 3926.40.00 and Section 338 Canada: Rates, Scope, and Stacking: parallel example of Section 338 overlay mechanics
• 4823.90.86 and Section 338 Canada: Rates, Scope, and Stacking: another Section 338 stacking example
• Post Entry Audit Program: Build a Monthly Self-Review That Catches Errors: practical audit framework for importers
• Customs Transaction Value: The Default Valuation Method Explained: valuation rules that determine the dutiable base