What Are Tariffs? How US Import Tariffs Work in 2026

A tariff is a tax on imported goods. In the United States, the importer of record pays it to US Customs and Border Protection (CBP) when the goods enter, usually as a percentage of their value. The rate depends on three things: the product's HTS code, its country of origin and the date it enters. In 2026, much of the duty on many products comes from additional Chapter 99 tariffs such as Section 232 and Section 301, on top of the regular base rate.

How a tariff works

When something is imported into the United States, CBP collects a duty on it before it can be released into the country.

That duty is almost always a percentage of the goods' customs value. A $10,000 shipment with a 5% tariff owes $500. Some products pay a fixed amount per unit instead, like 3.4 cents per kilogram, and a few pay both.

Who pays tariffs?

The importer of record pays. That's the company or person responsible for the goods when they enter the US, usually the buyer, sometimes a customs broker or a seller shipping on the buyer's behalf.

The foreign seller doesn't send money to the US government. In practice the cost spreads out: importers raise prices, suppliers sometimes cut theirs, and customers often end up paying some of it. But the legal obligation, and the risk of getting it wrong, sits with the importer.

How US tariff rates are set

Every product that enters the US is classified under a code in the Harmonized Tariff Schedule of the United States (HTSUS), published by the US International Trade Commission. The code is 10 digits long. The first six are shared worldwide (the Harmonized System); the last four are specific to the US.

For a given product, three things set the duty:

1. The HTS code. It decides the base rate. A cotton T-shirt (6109.10.00) pays 16.5%; most medicines pay nothing.
2. The country of origin. Where the product was made, which isn't always where it shipped from. Origin decides which column of rates applies and which additional tariffs kick in.
3. The entry date. Rates change. The duty is set by the rules in force on the day the goods enter.

The value matters too, since most rates are a percentage of it.

Base rates: the three columns of the HTS

Each line of the HTS has three rate columns:

The General rate is what most people mean by "the tariff" on a product. For many goods it's modest, often under 5%.

Additional tariffs in 2026: Chapter 99

On top of the base rate, the US adds tariffs through Chapter 99 of the HTS. Each one has its own heading, like 9903.82.02, with legal notes that say which products and countries it covers. These are where the big numbers come from.

As of October 2026, the main ones in force are:

• Section 232 (national security): steel, aluminum and copper (usually 50%), autos and auto parts (25%), heavy trucks, semiconductors, wood products, patented pharmaceuticals (from July 31, 2026) and drones (from September 3, 2026), with lower all-in rates for some trading partners.
• Section 301 China: 7.5% to 100% on most Chinese goods, depending on the product.
• Section 301 forced labor: from July 24, 2026, 10% or 12.5% on goods from 59 countries and the EU, including China, Vietnam, India, Canada and Mexico. For the EU, Japan, South Korea, Taiwan and Switzerland it's an all-in rate of 10% or 12.5% including the base rate.
• Section 301 Brazil: 25% on Brazilian goods, from July 22, 2026.
• Section 338 Canada: 50% on a list of Canadian products, from August 22, 2026. Since September 29, some of them are banned from import entirely.
• Section 201 quartz: a safeguard on quartz countertops and slabs from August 15, 2026: 25% in quota, 50% over quota.

Several of these come with exemptions, and some replace others instead of adding to them. Our guide to US tariff stacking rules walks through how they combine, and the latest US tariff changes lists every change in 2026 with its date.

Customs fees on top of duty

Two customs fees apply to most commercial imports:

• Merchandise Processing Fee (MPF): 0.3464% of the value on formal entries, with a minimum of $34.58 and a maximum of $670.86 for fiscal year 2027, which started October 1, 2026.
• Harbor Maintenance Fee (HMF): 0.125% of the value, on ocean shipments only.

Why tariffs are hard to calculate correctly

The math itself is simple. Knowing which rules apply is the hard part:

• The schedule changes all the time. The HTS was revised 20 times in 2026 through the end of September, and most revisions changed at least one Chapter 99 tariff.
• Exemptions depend on facts about your goods. Whether a product contains steel, whether a drug is generic, whether goods qualify for USMCA: each can move the duty rate by 10% or more.
• Programs interact. Some tariffs stack. Others switch off when a Section 232 tariff applies. Getting the order wrong gives you the wrong total.

That's why an HTS code and a headline rate aren't enough to price an import. You need the full stack, for your specific code, origin and date. Our guide to how US tariffs are calculated shows the whole process with real numbers.