The Section 301 Four-Year Review: What's Coming for China Tariffs Through 2027

Domestic industries that benefit from Section 301 tariffs (the China-specific duties first imposed in 2018) have to ask the government to keep them. That's the mechanic driving everything in this post: a formal request process, with submission windows that closed and reopened on a schedule, determines whether tariffs expire or continue. Right now, the second window is open, and it runs through August.

This piece breaks down what already changed on January 1, 2026, what's under review now, and what to watch through 2027.

What the Four-Year Review Is

Statutory basis under Section 301

Section 301 of the Trade Act of 1974 gives the U.S. Trade Representative (USTR, the federal office that negotiates and enforces trade agreements) authority to impose tariffs in response to unfair foreign trade practices. The original China tariffs under this authority went into effect in 2018, covering thousands of product lines across multiple "tranches" (the sequential lists USTR published, often referenced by their action dates, like July 6, 2018, or August 23, 2018).

The statute includes a built-in check: tariffs don't run indefinitely without reauthorization.

USTR's review obligation

After four years, USTR must determine whether to continue the tariffs. The mechanism isn't automatic renewal. Instead, USTR requires domestic industries that benefit from a given tariff action to formally request its continuation, or the tariff is set to expire.

That puts the burden on industry as opposed to the importers to keep the duties in place. If no domestic petitioner asks for continuation on a given tariff line, it can lapse.

Summary of the first four-year review (2024) and what it produced

The first review concluded in 2024 and resulted in a set of targeted rate increases rather than a wholesale tariff expansion. 

• Electric vehicles saw tariffs rise by 100%. 

• Solar cells and semiconductors rose by 50%. 

• Batteries, critical minerals, and steel and aluminum products rose by 25%.

USTR also created a narrower exclusion process during that review, covering specific manufacturing machinery under HTS (Harmonized Tariff Schedule, the numeric system used to classify imported goods) Chapters 84 and 85, along with solar manufacturing equipment. 

The 2026 Rate Hikes That Already Took Effect (January 1)

The first review's rate increases didn't all land at once. A batch of them phased in on January 1, 2026, and importers in the affected categories are now paying the new rates.

Non-EV lithium-ion batteries (7.5% → 25%)

Lithium-ion batteries outside the electric-vehicle category jumped from a 7.5% tariff to 25%. This covers a wide range of consumer and industrial battery products, not just the EV-specific cells that were already targeted in the first round of increases.

Natural graphite and permanent magnets (0% → 25%)

These two categories went from no Section 301 tariff to 25%. Both are critical inputs for batteries and motors, which is part of why they're flagged again under "likely rate changes" below.

Enteral syringes (0% → 100%)

Enteral syringes (used for feeding rather than injections) went from duty-free to a 100% tariff. This is one of the steepest jumps in the entire 2026 batch, and it lands on a medical product category that doesn't always get the same trade-press attention as semiconductors or batteries.

Disposable textile facemasks (7.5% → 50%)

Disposable textile facemasks rose from 7.5% to 50%. Importers who shifted sourcing during the pandemic-era PPE shortages should check whether their current supply chain still routes through China for this category.

(If your business imports any of the products above, a tool like Gaia's Tariff Engine can model what the new rate does to landed cost before it shows up on an entry.)

The Second Review Underway (May 2026 Onward)

USTR's review scope and procedural calendar

The second four-year review covers tariff actions that haven't yet gone through this reauthorization process, including the original July and August 2018 tranches. USTR is requiring domestic industries to file continuation requests on a staggered timeline tied to each original action's date.

For the July 6, 2018 action, the request window runs from May 7, 2026 to July 5, 2026. For the August 23, 2018 action, the window runs from June 24, 2026 to August 22, 2026. Tariff lines without a continuation request filed in the relevant window are positioned to expire.

Stakeholder comment process

Once continuation requests are filed, USTR opens a public comment period. Importers, downstream manufacturers, and other affected parties can weigh in on whether a given tariff should continue, change, or lapse, separate from the domestic industry petitions themselves.

Public hearing timeline

USTR has historically paired review periods with public hearings where stakeholders testify directly. Specific hearing dates for this round hadn't been published at the time of writing, so importers with a stake in a particular HTS line should monitor the Federal Register for notices tied to their product category.

Likely Rate Changes Through 2027

Based on the pattern from the first review and the petitions filed so far, a few categories look likely to see rate action by 2027. None of this is confirmed, and actual outcomes depend on USTR's final determinations.

Solar (HTS 8541): scope extensions likely

Solar cells already saw a 50-point increase in the first review. Industry petitions for the second review have pushed for broadening scope within HTS 8541 (the chapter covering diodes, transistors, and semiconductor devices, which includes solar cells) to capture adjacent components that weren't covered the first time.

Critical minerals: tungsten, cobalt, rare earths

Natural graphite and permanent magnets moved from 0% to 25% in January. Other critical minerals, including tungsten, cobalt, and rare earth elements, are named in several continuation petitions as candidates for similar treatment, given their overlap with the battery and defense supply chains already targeted.

Pharmaceuticals: APIs and finished dosage forms

Active pharmaceutical ingredients (APIs, the chemical compounds that produce a drug's intended effect) and finished dosage forms have drawn increased petition activity, partly driven by broader U.S. policy interest in reshoring pharmaceutical manufacturing. 

Enteral syringes already jumped to 100% in January, and that may be an early signal for the wider medical-device-adjacent category.

Electronics: HTS 8471, 8473, 8517 likely revisions

HTS 8471 (automatic data processing machines, e.g. computers), 8473 (parts and accessories for those machines), and 8517 (telephone sets and other communication apparatus) are all referenced in petitions as candidates for revision. Given that semiconductors already doubled to 50%, downstream electronics assemblers are watching this chapter closely.

Sectors at Highest Risk of New Lists

Beyond rate increases on existing lines, some sectors face a different risk: being added to Section 301 coverage for the first time, or having narrow existing coverage expanded into a full product list.

Quantum and AI hardware

Quantum computing components and AI-specific hardware (specialized chips and accelerators) sit at the center of current U.S.-China technology competition. 

Neither category has comprehensive Section 301 coverage today, but both are referenced in policy commentary as candidates for a future list.

Advanced semiconductor packaging

Packaging technology, the processes that assemble individual chips into finished components, has drawn separate attention from chip fabrication itself. 

Some industry filings argue that packaging deserves its own tariff treatment distinct from the semiconductor rate that already doubled in January.

Clean energy components (BESS, wind, hydrogen)

Battery energy storage systems (BESS), wind components, and hydrogen-related equipment overlap with the battery and critical mineral categories already under upward pressure. A new list targeting clean energy infrastructure specifically, rather than just the inputs, has been floated and confirmed in trade press.

Medical devices

Broader medical device categories have seen significant Section 301 action. The USTR finalized major tariff modifications that phase in massive duty increases on a variety of critical medical goods imported from China.

Exclusion Process and Stakeholder Engagement

How to file an exclusion request

USTR's exclusion process lets importers request relief from a specific tariff line, typically by demonstrating that the increase causes disproportionate economic harm or that no viable non-China sourcing option exists. 

The first review's exclusion process targeted manufacturing machinery under HTS Chapters 84 and 85, plus solar manufacturing equipment specifically. It has been confirmed that the second review opens a similarly scoped exclusion.

Justifying with supply chain unavailability

The strongest exclusion requests tend to document, with specificity, why an alternative supplier outside China isn't available at comparable cost or quality within a reasonable timeframe. Generic hardship claims carry less weight than requests that show concrete sourcing attempts and their outcomes.

Coalition advocacy through trade associations

Individual importers, especially smaller ones, often have more influence filing jointly through a trade association than filing alone. Associations can aggregate data across member companies, which gives USTR a clearer picture of sector-wide impact than a single company's comment.

Building a 301 Forward Forecast Into Your Sourcing Model

Probability-weighted rate scenarios by HTS chapter

Rather than treating tariff rates as fixed, importers exposed to multiple HTS chapters under review can model a range of outcomes, weighting each by how likely it seems based on the petition activity and prior review patterns described above. This turns a binary "what if" into a range that can feed directly into cost forecasting.

China-vs-alternate-country sourcing math

The sourcing decision isn't just current landed cost versus an alternate country's landed cost. Its current cost against a probability-weighted range of future China costs, compared against the alternate country's cost plus the operational cost of switching suppliers.

Diversification triggers (rate-jump thresholds)

Some importers set a specific rate threshold (for example, a 20-point jump) as a trigger to formally evaluate alternate sourcing, rather than reacting case by case each time a new rate takes effect. Building that threshold into a sourcing policy ahead of time removes some of the scramble when a review concludes.

(For businesses tracking exposure across dozens or hundreds of HTS lines, Gaia's Classification Engine can help confirm the correct codes feeding into that kind of forecast, since rate changes are only as useful as the classification they're applied to.)

FAQs

When will the second four-year review conclude?
USTR hadn't published a final determination date at the time of writing. Based on the first review's timeline, a conclusion sometime in late 2026 or 2027 is plausible, but not confirmed.

Can rate hikes apply retroactively?
Section 301 rate changes have generally applied prospectively, from a specified effective date forward, rather than retroactively to past entries. Importers should still confirm the effective date for any specific tariff line before assuming a shipment is or isn't covered.

How do I know if my HTS is under review?
USTR publishes notices in the Federal Register listing which tariff actions are under review and the relevant comment windows. Checking your specific HTS codes against those notices, or against continuation petitions filed by domestic industries, is the most direct way to confirm exposure.

What's the typical exclusion approval rate?
Historical exclusion approval rates have varied significantly by product category and review round. Rather than relying on an average, it's more useful to look at approval patterns within your specific HTS chapter from the first review.

Will the next Administration unwind the increases?
That depends on policy decisions made by the USTR. What's worth tracking is the statutory mechanism itself: continuation requires industry petitions, so a lack of future petitions could lead to expiration regardless of which administration is in office.