8402.90.00.90—Steam or other vapor generating boilers (other than central heating hot water boilers capable also of producing low pressure steam); super-heated water boilers; parts thereof, parts, otherGeneral
4.3%
Units
kg
Column 2
45%
Special
Free (A,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG)
HTS 8402.90.00.90 is the U.S. Harmonized Tariff Schedule classification for Steam or other vapor generating boilers (other than central heating hot water boilers capable also of producing low pressure steam); super-heated water boilers; parts thereof, parts, other. It's a 10-digit statistical line 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, used by U.S. Customs and Border Protection to determine the duty rate at entry. 2 Chapter 99 tariff modifications currently stack on top of the base rate.
New to HTS codes? Read our guide on how HTS classification works →
Chapter 99 overlays that stack on the base rate
| Code | Authority | Rate |
|---|---|---|
| 9903.88.01 | section_301 | The duty provided in the applicable subheading plus 25% |
| 9903.88.11 | section_301 | The duty provided in the applicable subheading |
Past CBP decisions classifying real products under this HTS code. Useful precedent when classifying a similar product — each ruling shows how CBP interpreted the code for a specific case.
The tariff classification of a pipe spool from South Korea
The tariff classification of Heat Recovery Steam Generator (HRSG) parts from China
Protest 2605-04-100013; Moisture Separator for Steam Generators
The tariff classification of parts of heat recovery systems from Korea, Thailand, Japan, Denmark and Singapore.
The tariff classification of casing panels, dampers and trusses for a heat recovery steam generator from Canada.
Source: CBP CROSS (view all rulings on rulings.cbp.gov →)
HTS 8402.90.00.90 is the U.S. Harmonized Tariff Schedule classification for Steam or other vapor generating boilers (other than central heating hot water boilers capable also of producing low pressure steam); super-heated water boilers; parts thereof, parts, other. It belongs to Chapter 84 of the HTSUS.
The general (Column 1) duty rate for HTS 8402.90.00.90 is 4.3%. This is the most-favored-nation (MFN) rate that applies to imports from World Trade Organization member countries.
Yes. Imports of HTS 8402.90.00.90 from countries party to a trade program (such as USMCA, KORUS, GSP, or the African Growth and Opportunity Act) may qualify for the special rate: Free (A,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG). Eligibility depends on rules of origin and certification.
The Column 2 rate for HTS 8402.90.00.90 is 45%. This rate applies to imports from countries that do not have normal trade relations with the United States (currently Cuba and North Korea).
Yes — HTS 8402.90.00.90 is covered by section_301 provision 9903.88.01 (The duty provided in the applicable subheading plus 25%). 1 additional overlay also touch this code. Open the code page for the full overlay stack with effective dates and country scopes.
No active AD/CVD orders currently flag HTS 8402.90.00.90 in Tandom's catalog. Tandom monitors Federal Register notices daily; a flag will appear here within 24h of any new order's publication.
Free Trade Agreement and special-program eligibility
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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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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