The Tariff Stacking Problem
Between April 2025 and February 2026, US importers faced the most complex tariff environment in modern history. A single shipment could be assessed duties under five separate programs, each authorized by a different statute and administered under different HTS provisions. The cumulative effect: effective duty rates exceeding 200% on some Chinese imports.
Now that IEEPA tariffs have been struck down, the challenge is decomposing these stacked assessments to isolate the refundable IEEPA component from the non-refundable layers. This is not a simple subtraction — it requires understanding which tariff programs apply to your specific HTS code and country of origin.
Visualizing Stacked Duties: China Import Example
A Section 301 List 1 product imported from China (e.g., industrial machinery, HTS 8479) faced the following cumulative assessment:
Total effective rate: 173.5% — of which 145% (83.6% of total duties) is recoverable as an IEEPA refund.
All Five Tariff Programs Explained
1. MFN (Most Favored Nation) Duty
The base tariff rate determined by the HTS classification of the product. Ranges from 0% (many raw materials) to 20%+ (certain textiles, footwear). Authorized under the Tariff Act of 1930. Not affected by the SCOTUS ruling.
2. Section 301 (China Trade Practices)
Additional 25% duty on Chinese imports across four lists covering approximately $370 billion in annual trade. Authorized under Section 301 of the Trade Act of 1974. Administered under HTS 9903.88.01–9903.88.04. Not affected by the SCOTUS ruling.
3. Section 232 (National Security)
25% on steel and 10% on aluminum imports from most countries. Authorized under Section 232 of the Trade Expansion Act of 1962. Administered under HTS 9903.80 subheadings. Not affected by the SCOTUS ruling.
4. IEEPA Tariffs (Reciprocal)
10%–145% additional duty depending on country of origin. Imposed under the International Emergency Economic Powers Act. Administered under HTS 9903.01 subheadings. FULLY REFUNDABLE after the SCOTUS ruling.
5. AD/CVD (Antidumping & Countervailing Duties)
Product-specific rates imposed on goods sold below fair value or subsidized by foreign governments. Authorized under Title VII of the Tariff Act of 1930. Rates vary widely by product and country. Not affected by the SCOTUS ruling.
Stacked Rate Examples by Country and Product
| Product / Origin | MFN | §301 | §232 | IEEPA | Total | Refundable |
|---|---|---|---|---|---|---|
| Electronics / China | 0% | 25% | — | 145% | 170% | 145% |
| Steel / EU | 0% | — | 25% | 20% | 45% | 20% |
| Apparel / Vietnam | 16% | — | — | 46% | 62% | 46% |
| Auto Parts / Japan | 2.5% | — | — | 24% | 26.5% | 24% |
| Furniture / China | 0% | 25% | — | 145% | 170% | 145% |
| Aluminum / India | 2.6% | — | 10% | 26% | 38.6% | 26% |
| Machinery / S. Korea | 3% | — | — | 25% | 28% | 25% |
| Chemicals / China + AD | 5.5% | 25% | — | 145% | 175.5%+AD | 145% |
Why Automated Isolation Matters
Manual calculation of stacked duty refunds is error-prone for three reasons:
- Overlapping applicability — Section 301 lists don't cover all Chinese goods. A product not on List 1–4A may only have IEEPA and MFN duties, changing the refund ratio entirely.
- Rate changes over time — IEEPA rates shifted multiple times between April and July 2025 as executive orders were amended. The applicable rate depends on the exact entry date.
- Exclusions and exceptions — Certain HTS codes were excluded from specific tariff programs. Section 301 exclusions, Section 232 product exclusions, and IEEPA exceptions all affect the calculation.
The IEEPA.co engine handles all of this automatically. Input your HTS code, country, and entry date — it identifies every applicable tariff layer and isolates the refundable IEEPA component.
Calculate Your Stacked Duty Exposure
Run your import data through the calculator to see the full breakdown: MFN, Section 301, Section 232, IEEPA, and the net refundable amount. All processing runs client-side — your data never leaves the browser.
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