The Supreme Court declared IEEPA tariffs unconstitutional on February 20, 2026. But the ruling didn’t tell CBP what to do next. It didn’t order refunds, didn’t set a timeline, and didn’t create a mechanism for returning $166 billion to 330,000 importers. That job fell to the Court of International Trade — and specifically to the case of Atmus Filtration Technologies v. United States.
On March 4, 2026, the CIT issued an order in Atmus Filtration that became the operational foundation for every IEEPA tariff refund. If the Supreme Court ruling was the legal victory, the CIT order was the instruction manual. Here’s what happened, what it means, and why it affects your recovery.
Who Is Atmus Filtration?
Atmus Filtration Technologies is a filtration products manufacturer — they make filters for diesel engines, industrial equipment, and commercial vehicles. Spun off from Cummins Inc. in 2023, Atmus is a significant importer of filtration components, many sourced from countries affected by IEEPA tariffs.
Atmus wasn’t the first company to challenge IEEPA tariffs at the CIT, but their case moved faster than others for several reasons. They had clean entry data, a clear IEEPA exposure profile, and aggressive legal counsel who recognized that the post-Supreme Court window was the moment to push for concrete relief.
The case was filed under 28 U.S.C. Section 1581(i), which gives the CIT jurisdiction over customs-related matters that don’t fit neatly into the protest or classification tracks. Atmus argued that waiting for CBP to voluntarily process refunds was inadequate — importers needed a court order compelling action.
Why This Case, Not Another?
Dozens of IEEPA-related cases were pending at the CIT when the Supreme Court ruled. The reason Atmus Filtration became the landmark order was partly timing and partly strategy. Their attorneys filed an emergency motion for injunctive relief within days of the Supreme Court decision, framing the issue as one of urgency: CBP had no published plan to return the money, and entries were continuing to liquidate with IEEPA duties assessed.
The CIT consolidated several pending motions and used Atmus Filtration as the lead case for addressing the universal question: what must CBP do now?
What the CIT Ordered on March 4
The March 4 order contained several directives that fundamentally shaped the refund landscape:
1. CBP must reliquidate affected entries. The court ordered CBP to reliquidate entries where IEEPA duties were assessed and where liquidation is “not yet final.” This covers entries that are either still unliquidated or that have been liquidated but are within the 180-day protest window under 19 U.S.C. Section 1514.
2. Refunds must include statutory interest. The order explicitly referenced 19 U.S.C. Section 1505(c), confirming that refunds aren’t limited to principal — CBP must pay interest from the date of deposit to the date of refund.
3. CBP must develop a processing mechanism. The court didn’t dictate the exact system, but it required CBP to establish and implement a procedure for processing refunds at scale. This directive is what led to the development of the CAPE system.
4. Status reporting requirements. CBP was ordered to provide periodic status reports to the court on refund processing progress. This keeps the government accountable and gives the CIT ongoing oversight authority.
The Scope: “Not Yet Final”
The most important phrase in the order is “not yet final.” A liquidated entry becomes final when the 180-day protest period expires without a protest being filed. Once final, the entry falls outside the scope of the March 4 order.
This is exactly why filing protective protests is so critical. A protested entry remains “not final” regardless of how long CBP takes to process the protest. An unprotested entry that passes day 181 becomes final and is excluded from the universal refund order.
If you take one thing from this article, let it be this: the March 4 order only helps you if your entries aren’t final. Filing a protest is how you keep them covered.
The March 6 Partial Stay
Two days after the order, the government filed an emergency motion for a stay pending appeal. On March 6, the CIT issued a partial stay that modified but did not eliminate the order’s requirements.
The partial stay affected the timeline for reliquidation — CBP was not required to begin issuing refunds immediately. But the stay did not affect the requirement to develop a processing mechanism, and it did not relieve CBP of the obligation to process refunds once the mechanism was in place.
What the Stay Means Practically
The partial stay created a pause, not a cancellation. CBP used this period to build the CAPE portal, develop internal processing procedures, and begin cataloging affected entries. The stay gave the government breathing room to stand up infrastructure rather than being forced to manually process hundreds of thousands of entries overnight.
For importers, the stay changed the timeline but not the outcome. Refunds are still coming. The CIT order still stands as the legal basis compelling CBP to act. The stay simply meant that the first refunds wouldn’t start flowing in March 2026 — they’d start flowing once CAPE was operational.
The practical impact is that importers who expected immediate relief after the CIT order had to recalibrate expectations. The IEEPA tariff refund timeline reflects the current realistic schedule for when refunds will begin disbursing at scale.
How the Order Led to CAPE
Before the March 4 order, CBP had no plan for processing IEEPA refunds at scale. The agency’s existing systems — ACE for entry processing, the protest module for individual challenges — weren’t designed to handle a universal refund event affecting 330,000 importers and potentially millions of individual entries.
The CIT order forced CBP’s hand. Within weeks of the order (and during the partial stay period), CBP announced the development of the Centralized Automated Processing Engine, or CAPE. This system is purpose-built for IEEPA refund processing and represents the largest single modification to CBP’s entry processing infrastructure in over a decade.
CAPE is designed to:
- Identify entries with IEEPA HTS codes (9903.01.xx and 9903.02.xx)
- Calculate the refund amount for each entry, including statutory interest
- Process refunds in bulk rather than entry-by-entry
- Interface with ACE to update liquidation records
- Generate disbursement instructions to Treasury
The CAPE queue and filing position article explains where the system stands today and how entries are being prioritized for processing.
The Accountability Mechanism
One of the most consequential aspects of the March 4 order is the reporting requirement. CBP must provide regular updates to the CIT on processing progress. This creates a judicial accountability loop — if CBP falls behind or deprioritizes IEEPA refunds, the court can intervene.
This is unusual. In most customs disputes, once the court issues an order, enforcement is ad hoc. The Atmus Filtration order built in ongoing oversight, which gives importers confidence that the refund process won’t stall indefinitely.
How This Affects Every Other Importer’s Claim
You don’t need to be Atmus Filtration to benefit from this order. The CIT issued it as a universal directive — it applies to all entries with IEEPA duties where liquidation is not yet final. Whether you’re a Fortune 500 company with $50 million in IEEPA exposure or a small importer with $50,000, the order covers your entries equally.
However, “covers” doesn’t mean “automatic.” The order creates the legal framework and compels CBP to act, but individual importers still need to ensure their entries are positioned for recovery. That means:
For unliquidated entries: File Post-Summary Corrections through your customs broker to remove IEEPA duty lines. This is the fastest path and doesn’t require waiting for CAPE.
For liquidated entries within the 180-day window: File protective protests immediately. This keeps your entries “not final” and within the scope of the order. The 180-day protest window is entry-specific — check your liquidation dates.
For entries approaching the 180-day deadline: These are urgent. Once the window closes, your entry falls outside the March 4 order’s scope. The only remaining path is CIT litigation, which is slower and more expensive.
For entries already past the 180-day window: You’ll need to pursue CIT litigation under 28 U.S.C. Section 1581(i). The Atmus Filtration order doesn’t directly cover these entries, but the legal precedent it establishes supports your constitutional claim.
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The Broader Legal Significance
Atmus Filtration v. United States is significant beyond IEEPA for several reasons.
Precedent for Universal Customs Relief
The CIT has rarely issued orders that apply universally to all importers, not just the parties to the case. The Atmus Filtration order does exactly that — it directs CBP to process refunds for all affected entries, not just Atmus’s. This creates a precedent for how courts might handle future large-scale customs disputes.
Judicial Oversight of CBP Operations
The ongoing reporting requirement is a form of judicial oversight that CBP typically doesn’t face. Customs operations are usually administrative — CBP processes entries, assesses duties, and handles protests without court supervision. The Atmus Filtration order puts a federal judge in the loop, which changes CBP’s incentive structure around processing speed and accuracy.
Interaction with the Supreme Court Ruling
The March 4 order translates the Supreme Court’s constitutional ruling into operational requirements. The Supreme Court said IEEPA tariffs are unconstitutional. The CIT said “and here’s what CBP must do about it.” This two-step process — constitutional ruling followed by operational order — is likely to become the model for how similar situations are handled in the future.
Lessons from the Atmus Litigation Strategy
The way Atmus Filtration approached this case offers practical lessons for every importer navigating the refund process.
Speed Mattered
Atmus’s legal team moved within days of the Supreme Court ruling. They didn’t wait for CBP to announce a refund process. They didn’t wait for other companies to go first. They filed an emergency motion while the legal landscape was still fresh and the court’s attention was focused on IEEPA.
For individual importers, the lesson is the same: don’t wait. Every day that passes without filing a protective protest is a day closer to the 180-day deadline. Every unliquidated entry that you don’t PSC is an entry that might liquidate before you act. The importers who move first protect their rights most effectively.
Universal Relief Was the Right Ask
Atmus didn’t just ask for its own refunds. Its attorneys framed the motion as requesting universal relief — an order directing CBP to process refunds for all affected importers. This was a strategic choice that benefited the entire importer community and positioned the case as the vehicle for resolving a systemic issue rather than an individual dispute.
The practical impact is significant. Because the order is universal, individual importers don’t need to file their own CIT cases to benefit from it. They need to ensure their entries are within the order’s scope (by filing protests and keeping entries “not final”), but the legal heavy lifting has been done.
Data Quality Was Essential
Atmus won partly because its entry data was clean. The company could identify every IEEPA-affected entry, calculate the duty impact, and present the information in a format the court could act on. If the data had been messy — wrong HTS codes, incomplete entry summaries, unreconciled accounts — the case would have been slower and less persuasive.
For your own recovery, data quality matters just as much. An Impact Assessment starts with pulling and validating your entry data. Clean data means faster processing, fewer disputes, and stronger positioning whether you’re pursuing PSCs, protests, or CIT litigation.
How the Order Interacts with Statutory Interest
The March 4 order’s reference to 19 U.S.C. Section 1505(c) is particularly important. By explicitly including statutory interest in the refund obligation, the court foreclosed any argument that CBP could return principal without interest.
Interest accrues from the date of deposit to the date of refund. For entries deposited in early 2025, that’s already well over a year of interest accumulation. At the statutory rate of approximately 5-6% for corporate overpayments, the interest component can add $50,000-60,000 per million dollars of IEEPA duties per year.
The order’s interest provision also affects the government’s incentive structure. Every day CBP delays processing refunds, the total interest liability grows. This creates financial pressure on the government to process refunds efficiently — a pressure that didn’t exist before the March 4 order made interest obligations explicit.
What Happens Next
The Atmus Filtration case isn’t over. Several developments are still pending:
Resolution of the partial stay: The government’s appeal of the CIT order is pending. If the Federal Circuit upholds the order (which is widely expected given the Supreme Court’s clear constitutional ruling), the stay will be lifted and CBP will be under full obligation to process refunds without further delay.
CAPE operational launch: CBP continues building and testing the CAPE system. The court’s reporting requirements ensure that progress updates are public and that delays are subject to judicial scrutiny.
Processing priority determinations: The order didn’t specify the order in which entries should be processed. CBP is developing its own priority framework within CAPE, which will likely prioritize entries with approaching deadlines and entries where protests have already been filed.
Individual entry disputes: While the universal order covers the broad principle (IEEPA duties must be refunded), individual entries may raise specific issues — classification disputes, valuation questions, or data discrepancies. These will need to be resolved through the normal protest and review process, not through the Atmus Filtration framework.
The Connection to Your Recovery
Understanding Atmus Filtration matters because it’s the legal basis for your refund. When your customs broker files a PSC or when you file a protest, the legal authority compelling CBP to process that refund traces back to this order. When CAPE processes your entries, it’s doing so under the framework established by the March 4 directive.
More importantly, understanding the order’s scope — specifically the “not yet final” limitation — tells you exactly what you need to do right now. If you have liquidated entries without protests filed, and the 180-day window is still open, filing that protest is the single most important action you can take.
The four recovery paths analysis shows how each path connects to the Atmus Filtration framework. The complete guide to IEEPA tariff refunds provides the full strategic picture.
Don’t assume your entries are covered automatically. Verify your entry statuses, file protective protests where needed, and ensure every eligible entry is positioned within the scope of the March 4 order.
