8409.91.99—Suitable for use solely or principally with spark-ignition internal combustion piston engines (including rotary engines), otherGeneral duty rate
2.5%
Across 2 10-digit lines
Coverage on this page
HTS 8409.91.99 is an 8-digit tariff item of the U.S. Harmonized Tariff Schedule covering Suitable for use solely or principally with spark-ignition internal combustion piston engines (including rotary engines), other. It sits in Chapter 84: Nuclear reactors, boilers, machinery and mechanical appliances; parts thereof, Section XVI: Machinery and Mechanical Appliances; Electrical Equipment; Parts Thereof; Sound Recorders and Reproducers, Television Image and Sound Recorders and Reproducers, and Parts and Accessories of Such Articles and rolls up 2 10-digit statistical lines, all with a general duty rate of 2.5%. 12 Chapter 99 tariff modifications currently touch one or more lines under this tariff item, and 3 AD/CVD orders flag at least one child line.
Pick a line to view full rate detail and compute landed duty
Chapter 99 overlays touching one or more lines under 8409.91.99
| Code | Authority | Rate |
|---|---|---|
| 9903.81.91 | section_232 | The duty provided in the applicable subheading + a duty of 50% upon the value of the steel content. |
| 9903.81.92 | section_232 | The duty provided in the applicable subheading. |
| 9903.81.98 | section_232 | The duty provided in the applicable subheading + 25% |
| 9903.88.01 | section_301 | The duty provided in the applicable subheading plus 25% |
| 9903.74.08 | section_232 | The duty provided in the applicable subheading + 25% |
| 9903.80.03 | section_232 | The duty provided in the applicable subheading + 25% |
| 9903.74.10 | section_232 | The duty provided in the applicable subheading |
| 9903.81.86 | section_232 | The duty provided in the applicable subheading + 25% |
| 9903.74.11 | section_232 | The duty provided in the applicable subheading |
| 9903.81.84 | section_232 | The duty provided in the applicable subheading + 25% |
| 9903.88.15 | section_301 | The duty provided in the applicable subheading + 7.5% |
| 9903.74.09 | section_232 | The duty provided in the applicable subheading + 25% |
Antidumping or countervailing orders covering one or more lines under 8409.91.99
A-570-119ADChinaCertain Large Vertical Shaft Engines Between 225cc and 999cc, and Parts ThereofA-570-124ADChinaCertain Vertical Shaft Engines, between 99cc and up to 225cc, and parts thereofC-570-125CVDChinaCertain Vertical Shaft Engines a Displaced, between 99 Cubic Centimeters and up to 225cc, and parts thereofHTS 8409.91.99 is an 8-digit tariff item of the U.S. Harmonized Tariff Schedule covering Suitable for use solely or principally with spark-ignition internal combustion piston engines (including rotary engines), other. It belongs to Chapter 84 and rolls up 2 10-digit statistical lines that brokers actually file at entry.
Every 10-digit line under HTS 8409.91.99 carries a general (Column 1) duty rate of 2.5%. Section 301, Section 232, and AD/CVD overlays may stack on top of this rate at the per-line level — open a specific 10-digit code to see its complete tariff stack.
U.S. Customs requires entries to be filed at the 10-digit statistical level — the broader tariff item HTS 8409.91.99 is not directly fileable. Match your product description to the most specific 10-digit line in the list on this page; if multiple lines could apply, the General Rules of Interpretation (GRIs) and chapter notes determine which one governs.
Yes — 3 AD/CVD orders flag at least one 10-digit line under HTS 8409.91.99. Whether a specific shipment falls in scope depends on the country of origin and the order's scope determination. See compliance.tandom.ai for full coverage detail.
Tandom guides relevant to this code
What the 178 active Section 301 exclusions cover, how to claim 9903.88.69 on an entry, and what changes when the November 10, 2026 deadline passes.
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How to read, order, and report Chapter 99 HTS codes alongside the base classification on a US entry summary in 2026. The full stacking ladder for brokers and compliance teams.
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A working guide to the inputs, the layers, and the math behind a US entry summary in 2026. Written for brokers, forwarders, and importer compliance teams.
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What changed April 6, 2026, what stayed the same, and how to file a steel, aluminum, or copper line in ACE without leaving duty exposure on the table.
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Where trade compliance APIs fit in a broker's filing pipeline: HTS classification, duty calculation, AD/CVD scope match, and post-summary corrections.
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Drop the Tandom Duty Calculator API into a TMS, broker software, or in-house ERP. Code samples, the response shape, and ACE reporting order, in 2026.
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