Supreme Court Lets China Section 301 Tariffs Stand: What List 3 and List 4A Mean for Importers Now

Executive Summary

On June 15, 2026, the U.S. Supreme Court declined to review the long-running challenge to Section 301 List 3 and List 4A tariffs on Chinese goods, ending nearly six years of closely watched litigation. The Federal Circuit’s ruling upholding the tariffs now stands as final. For importers, the practical message is clear: these China duties remain in force, thousands of suspended protests will be resolved without refunds, and new Section 301 investigations are already underway.

Intro 

For nearly six years, importers had one quiet hope working in the background. Maybe the courts would throw out the List 3 and List 4A tariffs, and maybe the duties paid since 2018 would come back. 

But on June 15, 2026, the Supreme Court closed that door for good.

The justices declined to hear the case. That single decision keeps the Section 301 tariffs on Chinese goods exactly where they are, and it ends the fight over whether they were ever valid.

If that feels familiar, it should. Tariff authority has bounced between the White House and the courts all year, and we tracked the same whiplash when the Federal Circuit revived the Section 122 tariff with a stay. Importers keep getting served with uncertainty where they hoped for relief.

So let’s get practical. What the court actually decided, what is still hitting your invoices, and what to do before the next wave of Section 301 tariffs arrives.

What the Supreme Court Did, and Didn’t, Decide

The case is HMTX Industries LLC v. United States, and the Supreme Court docket shows the denial in one line, with no explanation attached. A denial is not the court agreeing with the tariffs. It just declines to weigh in, which lets the lower ruling become the final word.

Now the part most headlines get wrong. This was never a swing at the Section 301 tariffs on China as a category. It targeted one specific move: whether the U.S. Trade Representative could bolt List 3 and List 4A onto the original action using its Section 307 modification power.

That narrow framing is the whole ballgame for importers. The duties are locked in, the courtroom route to a refund is gone, and the job now is managing what you owe instead of fighting it.

How the List 3 and List 4A Tariffs Came to Be

To see why the court was comfortable walking away, rewind to 2017. A USTR investigation found China forcing technology transfers and lifting intellectual property. Washington hit back with 25% duties on about $50 billion of imports, the first round, which nobody in this case bothered to challenge.

China retaliated, and instead of opening a fresh investigation, USTR used Section 307 to simply modify what it already had. That shortcut produced List 3 (10%, then 25%, on roughly $200 billion) and List 4A (10%, then 7.5%). The play-by-play sits in the Federal Circuit’s decision.

Importers argued that a modification power should not stretch into a tenfold expansion. The Federal Circuit disagreed on every count, including the constitutional ones, and that ruling is now the law importers live with.

What Stays in Place 

So what does this cost you in real life? All four lists are still active, hitting roughly $370 billion in Chinese-origin goods at rates from 7.5% up to 100%. USTR keeps the current breakdown on its Section 301 tariff actions page.

The biggest numbers land on strategic goods:

• Electric vehicles at 100%
• Semiconductors and solar at 50%
• Steel, aluminum, batteries, and critical minerals at 25%. 

If you move flooring, furniture, electronics, or industrial and manufacturing inputs, you are almost certainly paying into this system.

One trap to sidestep: do not lump these in with the IEEPA tariffs. Those got struck down and are being refunded, which we covered when that ruling dropped. Section 301 is a different law with a different ending.

These duties stack on top of your regular rates, so build your landed cost as if they are permanent.

What Happens to the Thousands of Suspended Protests

Plenty of importers filed protective protests during the case, hoping to grab a refund if the challenge won. More than 4,200 related suits stacked up behind the lead case too. All of it now flows back into CBP’s normal process, laid out on its Section 301 trade remedies page.

The news there pulls no punches. The tariffs survived, so those protests were denied and not paid. If you wrote a List 3 or List 4A refund into a forecast, that line is gone.

This is exactly where people get tangled, because the IEEPA refund track is still open and runs on its own timeline. We mapped how to juggle CAPE claims, protests, and liquidation deadlines separately.

On the Section 301 side, the smart housekeeping is simple. Check your liquidation status and close those protective filings cleanly.

What Comes Next: New Section 301 Investigations and the July Deadline

The old fight is over, but Section 301 is just getting warmed up. In March 2026, USTR launched two fresh investigations, one into structural excess capacity across 16 economies and one into forced-labor imports spanning 60 trading partners. Both live on USTR’s Section 301 investigations hub.

We broke down what those probes signal for sourcing the week they opened. The short version: new duties could land by late July, right as the Section 122 tariffs expire, and they may reach more countries at higher rates than the ones you know today.

The importers who handle this well will not sit around refreshing the docket. They will spread out their sourcing, audit their classifications before the rates change, and keep their networks flexible enough to move when the next notice drops.

Where Mallory Alexander Fits Into What Comes Next

A finished case isn’t all bad. You finally know where you stand, and that’s a lot easier to plan around than another year of maybes. Refunds through this case are off the table, so the move now is squeezing every legal edge out of the rules you’ve got.

That’s where we come in at Mallory Alexander. 

Our licensed customs brokerage keeps your entries clean, so one bad classification doesn’t strand a container at the port. Our trade management and compliance team works your duty strategy, while our managed logistics crew helps you move sourcing around before the next rate shows up.

You’ve also got ways to soften the hit. Our warehousing and distribution network runs foreign-trade zones that can defer or shrink what you owe, with the same team handling your freight from the dock to the final stop.

We’ve handled trade like this for over 100 years, fully licensed and C-TPAT certified, and we send the updates that keep you ahead of the next headline instead of scrambling after it. Subscribe, and we’ll get the next one to you before it hits your costs.

And as always, if you want a real number on your Section 301 exposure, reach out to us. We’ll show you what you’re really paying, help you close out those protests the right way, and build a sourcing plan before the next deadline sneaks up on you.