US National Debt Crosses $40 Trillion, Hitting Consumers' Mortgages and Loans

The growing debt is already hitting American households. Lenders, Quakenbush said, are asking taxpayers to pay more for what the government borrows, which raises the cost of debt for everyone. "If a mortgage is out of reach, or financing for your business has gotten more expensive, the debt is part of the reason," he said.

The Yale Budget Lab modeled the effect of federal debt growth from 2015 through 2025. It found the increase raised annual costs by $2,500 for the median home mortgage and $120 for the average auto loan. Abhi Gupta, who co-authored the analysis, said while $40 trillion is hard to conceptualize, it amounts to upward of $100,000 per person. "In the same way homeowners take seriously the responsibility of making their mortgage payments, the national debt is large enough to deserve a similar level of consideration," he said.

The Treasury did not comment on whether the $40 trillion mark would alter its borrowing plans. The next quarterly refunding announcement is scheduled for August.