Warnings that the rising U.S. federal debt will lead to economic catastrophe are heard with increasing frequency. Former Office of Management and Budget Director Mitch Daniels, for example, recently wrote: “With debts already about to surpass the nation’s entire GDP ... only a dwindling number of denialists doubt that a cataclysmic reckoning … lies ahead,” (Daniels 2024). In this paper, we examine the various channels through which debt can affect the economy to assess the risk that elevated debt will lead to a crisis. We begin with a summary of the fiscal challenges facing the United States. We then review the costs of debt from a standard macroeconomic model and outline the scenarios that could lead to a crisis. Our analysis suggests the most likely consequences of the projected debt accumulation are those described by the standard macroeconomic model: Higher debt reduces the size of the capital stock and national wealth, benefiting current generations at the expense of future generations […]