How much debt reduction will this year's tariffs actually deliver?
Core argument: CBO projects tariffs enacted this year will reduce debt, including interest, by $3.0 trillion through FY2035, down from $4.0 trillion in August, with revenue excluding dynamic effects falling from $3.3 trillion to $2.5 trillion.
Updated projections from the CBO show that tariffs enacted this year will reduce debt (including interest) by $3.0 trillion through Fiscal Year (FY) 2035, down from the $4.0 trillion projected in August. Excluding dynamic effects, CBO now projects $2.5 trillion of revenue as opposed to $3.3 trillion – with 1/3 of the difference driven by announced policy changes and the other 2/3 due to an increased estimate of the share of imports that can access lower or zero duty rates under the United States-Mexico-Canada Agreement (USMCA), reduced estimates of the value of steel and aluminum in goods subject to tariffs on derivative products, and [a rise] in the projected share of tariff costs absorbed by foreign exporters from 0% to 5% of the increase in the tariff rate. If the Supreme Court upholds the ruling that tariffs enacted under the International Emergency Economic Powers Act (IEEPA) are illegal, then the primary deficit impact would likely drop to around $0.7 trillion, or roughly $0.9 trillion after interest. In light of CBO’s updated tariff estimates and the incorporation of actual 2025 budget data from Treasury, we now project debt to rise to 122% of GDP by 2035, roughly 2% of GDP higher than the CRFB Adjusted August Baseline and 4% of GDP higher than CBO’s January 2025 baseline. If the Supreme Court rules IEEPA tariffs illegal, debt would rise further to 127% of GDP.

