GlossaryBudget & spending
Social Security trust funds
Accounts that hold Social Security’s accumulated surpluses as special Treasury securities. They are the largest component of intragovernmental debt and are projected to run short in the 2030s.
Two funds, one promise
Social Security is financed mainly by a payroll tax shared by workers and employers, plus part of the income tax paid on benefits. The money is credited to two accounts: the Old-Age and Survivors Insurance fund, which pays retirement and survivor benefits, and the much smaller Disability Insurance fund. Benefits are paid out of these funds.
For decades the program collected more than it paid, largely because the baby boom generation was working. Those surpluses were invested in special Treasury securities that earn interest and can be redeemed at any time. The reserves became the largest single component of intragovernmental debt.
The turning point
As that generation retires, benefits have grown faster than dedicated income. The funds now cover the difference by redeeming their securities, and the Treasury pays them by borrowing from the public or using other revenue. The reserves are shrinking rather than growing.
The trustees’ 2025 report projected that the retirement fund on its own would be depleted in 2033 and the two funds combined in 2034. The 2026 report kept the combined date at 2034.
What depletion would mean
Depletion does not mean Social Security stops paying. Payroll taxes keep arriving. But the program cannot legally pay more than its funds hold, so benefits would have to be cut to match income. The 2025 report estimated that about 77 percent of scheduled retirement benefits, or 81 percent for the two funds combined, would still be payable at that point.
Congress has faced this kind of deadline before. In 1983, with reserves close to running out, it raised payroll taxes, began taxing some benefits and gradually raised the retirement age. Any fix now involves a similar mix, and each year of delay makes the necessary changes larger.