The United States now faces levels of public borrowing that are large relative to the size of the economy. Gross federal debt surpassed $40.0 trillion on August 18, 2026, while debt held by the public was about $32.3 trillion—approximately equal to one year of national output. These headline numbers matter less on their own than how they interact with saving, interest rates, investment and incomes over time.
This article explains the mechanism known as crowding out shows the practical channels through which government borrowing raises costs for households and businesses, and summarizes key projections from federal budget analyses that illustrate the potential long-run economic effects.
How government borrowing competes with private investment
Crowding out occurs when government borrowing draws on the same pool of funds that would otherwise finance private investment. When the Treasury issues additional securities to cover deficits, lenders face a choice: buy relatively risk-free Treasuries or lend to firms and households. To attract capital away from Treasuries, private borrowers must offer higher yields, which lifts interest rates across the economy. Some of the increase in demand for funds is met by higher household saving and by foreign investors, but these responses only partially offset the reduction in available private capital.
Beyond the direct competition for savings, rising federal debt can change investor expectations. Elevated debt levels may increase concern about future inflation or the possibility of policy actions that reduce bondholder returns, such as unexpectedly large money creation. Lenders price these risks into longer-term yields, pushing up borrowing costs for mortgages, corporate bonds, and student loans. At the same time, foreign purchases of U.S. debt can strengthen the dollar, making exports less competitive and shifting demand away from domestically financed investment.
Concrete effects across the economy
The upward pressure on yields from larger federal borrowing shows up in multiple, tangible ways. Yields on longer-dated Treasuries move higher as markets absorb new issuance, which raises the government’s own interest costs and crowds out private borrowers. That increased cost of capital reduces the number of profitable long-term projects firms are willing to undertake.
Examples of real-world impacts include fewer new housing starts because builders face more expensive construction finance; businesses postponing purchases of energy infrastructure and factory equipment; pharmaceutical and medical-technology firms paying more to fund research and development; universities confronting costlier financing for new labs; students facing higher interest charges on loans; and higher rates on mortgages, auto loans, credit cards and small-business lines of credit. Each of these channels reduces the
Who holds the debt and why ownership matters
Ownership patterns shape how the costs of debt are distributed. Roughly 32 percent of publicly held debt is owned by foreign entities, about 55 percent by domestic private and public investors, and roughly 14 percent by the Federal Reserve. Foreign-held U.S. debt amounts to about $9.4 trillion with Japan and the United Kingdom holding notable shares—about $1.2 trillion and $930 billion, respectively—and other major holders including China, Belgium and Canada. The Federal Reserve’s holdings were about $4.5 trillion at the time of the most recent accounting.
Projections and the long-term cost to incomes
Estimates from budget agencies illustrate the potential scale of the economic drag. Under recent federal projections, gross debt as a share of GDP is forecast to rise substantially over the coming decade and beyond; one projection put gross debt near 126 percent of GDP today and rising further by 2036. Debt held by the public is currently about 100 percent of GDP and is projected to climb toward roughly 120 percent of GDP by 2036 under a long-term outlook.
Analyses that quantify the growth effects find that higher debt ratios are associated with modest but persistent increases in long-term interest rates. For example, a widely used estimate suggests that a one percentage-point increase in the debt-to-GDP ratio raises long-term rates by about two basis points. Over longer horizons, that differential compounds: one public analysis estimated that holding debt constant at 100 percent of GDP rather than allowing it to follow a higher projected path could raise real income per person by roughly 4 percent in midcentury terms. In practical terms, that difference would appear as slower growth in paychecks and higher monthly borrowing costs spread out over decades.
The composition of federal obligations also matters. About $7.8 trillion of federal liabilities are intragovernmental—debts the government owes to its own trust funds, such as the Social Security OASI securities of about $2.2 trillion. Those balances are accounting assets for programs that rely on them, but they do not relieve the crowding-out pressure that arises from debt held by private and foreign investors.
Understanding the interplay between these numbers—the gross federal debtdebt held by the public ownership shares, and projected trajectories—helps explain why rising federal borrowing matters beyond headline totals. The key takeaway: when government debt grows faster than the economy for long stretches, it tends to push up borrowing costs and reduce the resources available for private investment, with consequences for economic growth and household budgets over many years.
