More than $175 billion in U.S. tariff revenues could be at risk of refund if the U.S. Supreme Court finds the administration's IEEPA-based tariffs unlawful, according to a Penn-Wharton Budget Model (PWBM) estimate produced for Reuters. The figure captures duties collected on imports under the Emergency Economic Powers Act and reflects a modeling effort that matches tariff rates to detailed import categories and countries of origin.
The PWBM calculation was built from the ground up, using tariff rates by product and by country for the specific duties imposed under President Donald Trump's measures, including those enacted under IEEPA. Lysle Boller, senior economist for the PWBM at the University of Pennsylvania, said the group's forecasting model relies on granular Census Bureau import data and statistical forecasting methods to produce its results.
How the estimate was produced
PWBM's model cross-references U.S. Census Bureau import records covering roughly 11,000 product import categories defined by eight-digit tariff codes and spans 233 countries. The model applies statistical forecasting to that dataset and arrives at an estimate of roughly $500 million in IEEPA-based revenue collected each day, according to PWBM.
As of Thursday, the model put total receipts tied to IEEPA duties since the first such tariffs were imposed in February 2025 at $179 billion. An alternate method used by PWBM - extrapolating prior U.S. Customs and Border Protection (CBP) IEEPA customs duty assessment data as a share of continuing U.S. Treasury customs receipts - produced a similar range of $175 billion to $176 billion.
Comparison with official CBP figures and fiscal context
CBP's last published assessments for IEEPA-based tariffs and other trade remedy duties, released on December 14, showed an at-risk total of $133.5 billion through that date. PWBM's estimate is higher, reflecting the continued flow of duties collected since mid-December and the group's forecasting approach.
PWBM noted that net duty collections are typically somewhat lower than the initial assessments because tariff assessments are subject to later adjustments and corrections that can produce refunds. The model also adjusts for abrupt tariff rate changes and policy shifts, which have occurred several times under the current administration.
Examples of tariff adjustments captured by the model
- The model incorporated a reduction in the U.S. tariff rate for South Korea from 25% to 15% that took effect in November.
- It also accounted for punitive duties imposed under IEEPA, such as a 40% tariff imposed last August on certain Brazilian goods, and the subsequent removal of duties on Brazilian coffee, beef and cocoa in November.
Legal timing and likely administrative consequences
The Supreme Court could hand down a decision on the legality of the IEEPA-based tariffs as early as Friday. If the court rules against the administration's use of IEEPA for these tariff measures, importers are expected to seek refunds from U.S. Customs and Border Protection for duties paid over the preceding year. Such a wave of refund claims would create administrative workload for CBP and fiscal implications for the Treasury.
Fiscal implications and Treasury response
PWBM highlighted that potential refunds in the range of $175 billion would be larger than total fiscal 2025 outlays for some major federal departments - for example, exceeding the Department of Transportation's $127.6 billion and the Department of Justice's $44.9 billion combined.
U.S. Treasury Secretary Scott Bessent told Reuters in January that the Treasury would be able to absorb tariff refunds if required, and that he was confident the Supreme Court would uphold the IEEPA tariffs. The Treasury is maintaining plans for sizeable cash balances as part of its borrowing strategy, targeting $850 billion at the end of March and $900 billion at the end of June.
Recent Treasury reporting has shown large gains in customs receipts in months following the introduction of the duties, with collections up by roughly $20 billion a month compared with prior-year periods before the duties were imposed. Total customs receipts in January were reported at about $27.7 billion.
Policy options if the court rules against IEEPA
Administration officials have indicated they would pivot to alternative tariff authorities to restore tariffs if the Supreme Court invalidates the IEEPA basis for the duties. That would be a separate administrative and legal course of action should the court decision force the removal of duties collected under IEEPA.
What remains uncertain
Key uncertainties are the timing and outcome of the Supreme Court decision and the scale and timing of any resulting refund requests to CBP. Additionally, initial tariff assessments are routinely adjusted, so the net fiscal impact could differ from the headline assessment numbers once those corrections are processed.
The PWBM estimate provides a detailed, data-driven view of the exposure tied to IEEPA-based tariffs, while Treasury statements and CBP publications offer complementary snapshots of collections and assessments. Should the court rule against the IEEPA measures, both administrative workload at CBP and the Treasury's cash management plans would be affected.