9903.08.21 UAS 232 Tariff: Rate, Scope, and Stacking

Key Points

• HTS 9903.08.21 imposes a 100 percent additional ad valorem duty on covered unmanned aircraft systems (UAS), docking stations, critical components, and thermal-imaging aircraft, effective 2026-09-03.
• The duty applies across all three duty columns, meaning it is not limited to most-favored-nation (MFN) imports.
• Sixteen underlying HTS lines are in scope, spanning Chapter 88 aircraft subheadings and two Chapter 85 electrical/electronic lines (8504409580 and 8537109170), each subject to a use-limitation gate.
• Parts for UAS with a maximum take-off weight (MTOW) above 25 kg are captured under U.S. note 43(c)(2), with certain excepted uses carved out from that sub-provision.
• Entries filed before 2026-09-03 are not covered; there is no announced end date for the 100 percent rate.

On this page

1. What 9903.08.21 is and which program created it
2. Affected products and HTS coverage
3. The 100 percent rate and its effective window
4. How 9903.08.21 stacks with other duties
5. How the code appears on a customs entry
6. What importers should do
7. Key references

HTS 9903.08.21 is a Chapter 99 overlay code that adds 100 percent ad valorem to imports of UAS, docking stations, certain critical components, thermal-imaging unmanned aircraft, and parts for heavy UAS, beginning 2026-09-03. The duty was established under the UAS 232 program by Proclamation 11055, published in the Federal Register at 91 FR 53699 (FR doc 2026-16979), and is structured through U.S. note 43(c)(1) through (c)(3). Any importer bringing in goods classifiable under the sixteen covered HTS lines on or after that date must report 9903.08.21 alongside the underlying Chapter 1-97 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 9903.08.21 is and which program created it

The UAS 232 program extends Section 232 national-security tariff authority to unmanned aircraft systems and related goods. Proclamation 11055, published at 91 FR 53699, is the controlling legal authority. It added U.S. note 43 to Chapter 99 of the Harmonized Tariff Schedule and created the 9903.08.21 subheading to carry the additional duty.

As of August 2026, this code is prospective: it takes effect on 2026-09-03 and has no announced expiration. Entries filed before that date are not subject to the additional duty.

Affected products and HTS coverage

The code covers goods described in U.S. note 43(c)(1), (c)(2), and (c)(3). Sixteen underlying HTS lines are in scope as of 2026-09-03, with no announced end date for any of them.

U.S. note 43(c)(1): UAS, docking stations, and critical components (Chapter 88 and Chapter 85 lines)

The following HTS lines are captured as UAS, docking stations, or critical components, and the Chapter 85 lines carry a use-limitation gate (the uasUse engine gate):

• 8504409580 (Chapter 85 electrical line, use-limited)
• 8537109170 (Chapter 85 electrical line, use-limited)
• 88062400
• 88062900
• 88069400
• 88069900

For the two Chapter 85 lines, the use-limitation gate means the additional duty applies only when the goods are imported for use as UAS or docking-station components, as defined in U.S. note 43(c)(1). Confirm the precise use-limitation language in the current HTSUS at hts.usitc.gov or with your broker.

U.S. note 43(c)(3): Unmanned aircraft with thermal-imaging capability

Six Chapter 88 subheadings covering unmanned aircraft with thermal-imaging capability are subject to a separate engine gate (thermalImaging). These lines apply a 100 percent charge by default:

• 88062100
• 88062200
• 88062300
• 88069100
• 88069200
• 88069300

U.S. note 43(c)(2): Parts for heavy UAS (MTOW above 25 kg)

Four Chapter 88 parts subheadings are in scope for UAS with a maximum take-off weight exceeding 25 kg. Certain excepted uses are carved out of this sub-provision; verify the exact carve-outs in the current HTSUS:

• 88071000
• 88072000
• 88073000
• 88079090

The 100 percent rate and its effective window

The additional duty under 9903.08.21 is 100 percent ad valorem, applied on top of any Column 1 (MFN), Column 1-Special, or Column 2 rate that already applies to the underlying Chapter 1-97 line. The rate applies across all three duty columns.

The rate takes effect on 2026-09-03. There is no announced end date. Proclamation 11055, published at 91 FR 53699, is the governing authority. Monitor the Federal Register and HTSUS for any modifications.

Because the duty doubles the dutiable value impact for high-value UAS and components, the customs value base matters greatly. Strategies such as first-sale valuation or freight deductions that lawfully reduce customs value will also reduce the 232 additional duty. See our related articles on first-sale customs valuation and customs value freight deductions for more detail.

How 9903.08.21 stacks with other duties

The 100 percent UAS 232 duty is additive. It stacks on top of:

• The standard MFN (Column 1) rate for the underlying Chapter 88 or Chapter 85 subheading.
• Any Section 301 China-origin additional duties that apply to the same goods, if the country of origin is China.
• Any other Section 232 additional duties already assessed on the same line, if applicable.
• Column 2 rates, if the goods originate from a country subject to Column 2 treatment.

The facts block confirms the 100 percent rate applies across all three duty columns, so there is no column-based escape from the additional duty. Country of origin, not country of export, governs which column applies. For goods with complex supply chains, confirm country of origin under the substantial transformation standard. See our overview of the substantial transformation test.

For context on how other Section 232 overlay codes interact with underlying duty columns, the metal-232 series articles (for example, 9903.82.10) illustrate the same stacking logic in a different product context.

How the code appears on a customs entry

Chapter 99 overlay codes like 9903.08.21 do not replace the underlying Chapter 1-97 classification. On a CBP Form 7501 (or its ACE electronic equivalent), each line carries two HTS numbers:

• The regular classification, for example 8806.24.00 (or whichever of the sixteen lines applies).
• 9903.08.21 as the additional Chapter 99 code, triggering the 100 percent duty on the same entered value.

The duty is calculated on the entered value at the time of entry summary. For the two Chapter 85 lines, the use-limitation gate requires that the import be for a qualifying UAS or docking-station purpose; CBP may request documentation supporting that declaration. For the Chapter 88 heavy-UAS parts lines, the excepted-use carve-outs in U.S. note 43(c)(2) require the importer or broker to confirm no exception applies before claiming the overlay code.

Check CBP.gov for any CSMS messages issuing filing instructions for 9903.08.21 ahead of the 2026-09-03 effective date. Our companion article on Section 232 UAS tariffs, drawback corrections, and ACE refund alerts covers ACE-filing specifics and refund posture.

Use our duty calculator to model the combined duty burden for a specific entry, and review the 2026 tariff code overview for other new Chapter 99 codes effective this year.

What importers should do

• Audit your purchase orders now. Identify any open orders covering goods classifiable under the sixteen HTS lines listed above that will arrive on or after 2026-09-03, and recalculate landed costs with the 100 percent additional duty included.
• Verify use-limitation and exception eligibility. For the two Chapter 85 lines and the heavy-UAS parts lines, prepare documentation showing the imported goods meet the required use or that an excepted use applies under U.S. note 43(c)(2); confirm the exact carve-out language in the current HTSUS at hts.usitc.gov.
• Brief your customs broker before 2026-09-03. Ensure your broker knows to add 9903.08.21 to every covered entry summary filed on or after the effective date, and monitor CBP.gov for any CSMS filing instructions specific to this code.
• Review your customs valuation posture. Because 100 percent doubles the duty impact of every dollar of entered value, lawful value-reduction methods (first sale, freight deductions) are especially worth reviewing ahead of the effective date.

Key references

• Proclamation 11055, 91 FR 53699 (FR doc 2026-16979): The governing proclamation establishing the UAS 232 program and creating U.S. note 43 and HTS 9903.08.21.
• Harmonized Tariff Schedule of the United States (HTSUS), hts.usitc.gov: Official text of U.S. note 43(c)(1)-(c)(3) and the 9903.08.21 subheading.
• U.S. Customs and Border Protection (CBP), cbp.gov: CSMS messages and ACE filing guidance for Chapter 99 additional duty codes.
• Federal Register, federalregister.gov: Source for the published proclamation text and any future modifications to the UAS 232 program.
• Section 232 UAS Tariffs, Drawback Corrections, and ACE Refund Alerts: CustomsGenius companion article on ACE filing, drawback, and refund posture for UAS 232 entries.
• Substantial Transformation Test: Country of Origin Explained: CustomsGenius guide to origin determination for multi-country UAS supply chains.