Import duty on diesel engine parts from China

Duty on a $10,000 entry of HTS 8409.99.99.90

An estimate for planning only: U.S. Customs and Border Protection (CBP) determines the final duty on your entry. Priced against tariff measures version 2026-10-06.

How much is the import duty on diesel engine parts from China?

A shipment of diesel engine parts classified under HTS 8409.99.99 and made in China currently pays a total of 37.50% in U.S. import duty. That total stacks 3 separate lines: the Column 1 general rate of Free (duty-free under the normal tariff), plus a Section 301 China list duty of 25.00% and the Section 301 forced-labor action of 12.50%. Additional duties compound on the same entered value, so the arithmetic is a sum of rates rather than a rate applied to a rate.

The duty stack, line by line

U.S. duty on this code is assembled from separate legal instruments, each with its own authority. Here is what each line on the entry is:

The base line is HTS 8409.99.99.90 itself at Free, the ordinary most-favored-nation rate that applies to every origin with normal trade relations with the United States.

HTS 9903.88.03 adds 25.00%: the Section 301 action against China, which charges an extra ad valorem duty on listed Chinese-origin goods on top of the normal rate — the engine's line reads "Section 301 China List 3".

HTS 9903.05.31 adds 12.50% under the Section 301 forced-labor action — in force since 24 July 2026 across 60 economies including China, charged on the entered value on top of the Column 1 rate and following the origin of the goods rather than the route they travel.

Worked example: a $10,000 shipment

Take one ocean shipment of diesel engine parts with an entered value of $10,000 — the customs value of the goods, before freight and insurance. At 37.50%, the duty is $3,750.00. Of that, $0.00 is the Column 1 duty and $3,750.00 is Chapter 99 additional duty. On top of the duty, the entry attracts a merchandise processing fee of $34.64 and, because it arrives by vessel, a harbor maintenance fee of $12.50. Duty and fees together come to $3,797.14, and the engine puts the landed cost of the goods at $13,797.14.

These are ad valorem rates, so a $100,000 entry of the same goods carries about $37,500 in duty, though MPF is capped per entry. Run your own value, entry date and HTS code through the import duty calculator for the same calculation against the same engine.

What changed, and when

The rate on this code has moved. Priced with an entry date of 15 October 2025, the same shipment would have paid 25.00%. Today it pays 37.50%, higher by 12.50 percentage points.

One thing that is often confused with this: IEEPA tariffs are not part of the calculation. The Supreme Court ruled against the IEEPA program on 20 February 2026, and this engine applies no IEEPA duty on any entry date. Every line above is Section 301, 232, 201 or 122 — separate statutes, unaffected by that ruling.

Between those two points sits the Section 122 balance-of-payments surcharge. Priced at 15 May 2026, inside the surcharge window, the same $10,000 entry would have paid 35.00% ($3,500.00), with the surcharge appearing as HTS 9903.03.01 at 10.00%. Section 122 ran from 24 February to 23 July 2026 and then expired by operation of law, so it does not apply to entries filed now. If you are reconciling a spring-2026 entry summary against a quote from today, that expired line explains most of the gap.

MPF, HMF and what else lands on the entry

Duty is not the whole bill to Customs. The merchandise processing fee is ad valorem with a statutory floor and ceiling per entry — $34.64 on this $10,000 example. The harbor maintenance fee is charged on vessel arrivals only, $12.50 here; the same shipment flown in would pay no HMF.

Not in any of these figures: antidumping and countervailing duties, excise taxes, quota charges, bond costs, and the freight and brokerage that make up the rest of your landed cost. AD/CVD is worth checking before you commit to a supplier — it is assessed on the producer and exporter, not just on the HTS code, and it can dwarf the tariff.

U.S. imports of 8409.99.99 from China

Between March and July 2026 the U.S. imported $613 million under HTS 8409.99.99 from the 55 origins in this dataset; $109 million of it — 17.8% — came from China, making China one of the larger suppliers on this subheading. The largest were Mexico (23.8%), Germany (18.2%), China (17.8%), India (10.3%) and Italy (5.5%).

Census also reports duty actually collected: entries of HTS 8409.99.99.90 from China paid an average effective duty of 39.24% of value over those months. That is above the 37.50% priced here, which usually points to other 10-digit lines in the subheading, or to measures that attach to the goods rather than the code — antidumping and countervailing orders being the usual cause. Treat it as a sanity check on your own numbers, not a forecast of your entry.

If you are moving this cargo rather than just pricing it, our China to USA shipping route page covers transit times, ports and documentation on the lane itself, and our Heavy Machinery & Industrial Equipment guide covers packing, classification and handling for this cargo type.

Planning around this number

Classification drives this: the page prices HTS 8409.99.99.90, the largest 10-digit line under 8409.99.99 for China by import value, and a neighboring line in the same subheading can carry different Chapter 99 exposure. Entry date matters as much as origin — the gap between the dates above is a change in law, not in your goods.

Airlift USA does not hold a U.S. customs broker license — customs entries are handled through our licensed broker network, and the broker of record makes the classification and origin calls. These figures are estimates for planning, produced by the same engine behind our import duty calculator; U.S. Customs and Border Protection determines the final duty on your entry.

How the duty on this shipment changed by entry date

What HTS 8409.99.99.90 covers

Parts suitable for use solely or principally with the engines of heading 8407 or 8408 > Other > Other > Other > Other > Other

Rates can differ from one 10-digit line to the next, so confirm your classification with a licensed customs broker before you rely on this figure. Other 10-digit lines under 8409.99.99: 8409.99.99.90, 8409.99.99.10.

Common questions about duty on HTS 8409.99.99 from China