Primary public expenditure in the United States is expected to remain relatively stable until 2030, within a range of 29–30% of GDP. The variations are due to the provisions of the One, Big, Beautiful Bill Act (OBBBA), notably the reform of student loans, whose downward effect on expenditure is concentrated in 2025, followed by increased security and defence spending from 2026 onwards.
On the revenue side, the tax structure inherited from the Tax Cuts and Jobs Act (TCJA, 2017) is preserved, with the addition of revenue from additional customs duties. As a result, the share of revenue in GDP is expected to grow by one percentage point to 28.3% between 2024 and the end of Donald Trump's term of office.
The increase in the public debt-to-GDP ratio is expected to continue but will be limited by continued high nominal growth. The real interest rate is the main cause of the increase in public debt due to its impact on interest charges, even though this effect remains lower in absolute terms than that exerted by real growth. As these effects increasingly neutralise each other over time, it is the level of the primary deficit that is expected to lead to a moderate increase in public debt.
