In 2023, the federal government spent $658 billion on net interest costs on the national debt. That total, which grew by 38 percent from $476 billion in 2022, was the largest amount ever spent on interest in the budget and totaled 2.4 percent of gross domestic product (GDP). Interest costs are on track to become the largest category of spending in the federal budget... In the late 1970s, the increasing national debt and higher interest rates led to a boost in interest costs, which reached a historic high of 3.2 percent of GDP in 1991 (looking at interest costs as...