For many Americans, the number barely registers. But budget experts warn it represents one of the most consequential—and least discussed—fiscal emergencies in the country’s history.
The numbers ahead are even more staggering. According to the Congressional Budget Office’s latest baseline, net interest costs are projected to more than double again, from $970 billion in fiscal year 2025 to $2.1 trillion by 2036.
By 2036, interest payments will consume one-quarter of all federal revenue, up from roughly one-fifth today and just one-tenth back in 2021. Put another way: For every four dollars the U.S. collects in taxes, one will go entirely toward paying creditors—not roads, not veterans, not schools.
The trajectory doesn’t stop there. By 2047, CBO projects interest costs will exceed even Social Security spending, ascending to become the single largest line item in the entire federal budget—larger than retirement income, larger than health care for seniors, larger than the military.
The consequences extend beyond accounting. As interest costs swell, they crowd out virtually every other national priority. The CRFB projects that rising interest costs will account for 28% of all nominal spending growth over the next decade and 120% of all spending growth as a share of GDP, meaning other programs will effectively shrink in relative terms just to make room.
The national debt currently stands at approximately $38.77 trillion as of February, growing at roughly $6.43 billion per day. At that pace, the U.S. is projected to hit $39 trillion by approximately April.
CRFB and other fiscal watchdogs argue that a credible deficit reduction plan remains the only viable off-ramp—one that would put debt on a sustainable path, ease pressure on interest rates, and prevent the interest bill from ultimately devouring the budget entirely. So far, Washington has not produced one.
For this story, Fortune journalists used generative AI as a research tool. An editor verified the accuracy of the information before publishing.
