Social Security trust funds

Social Security trust funds are the two federal accounts used to record the income and expenditures of the U.S. Social Security program and to hold its accumulated reserves. The funds are the Old-Age and Survivors Insurance (OASI) Trust Fund, which finances retirement and survivor benefits, and the Disability Insurance (DI) Trust Fund, which finances benefits for eligible disabled workers and their families. The U.S. Department of the Treasury manages both accounts; the Social Security Administration administers the program. ^[1][2]

Structure and purpose

The OASI and DI funds are legally distinct. OASI began in 1937 and DI in 1957. They track revenue and costs associated with the benefits assigned to each fund and hold accumulated reserves. The Social Security Act limits trust fund expenditures to program benefits and administrative costs. The funds do not represent separate investment accounts belonging to individual workers or beneficiaries; rather, they are federal accounts holding program reserves and recording transactions. ^[1][2]

The two funds are overseen by the Social Security Board of Trustees. The Board includes the Secretaries of the Treasury, Labor, and Health and Human Services, and the Commissioner of Social Security, who serve by virtue of their federal offices, as well as two public representatives appointed by the President and confirmed by the Senate. The Secretary of the Treasury is the managing trustee. The Board reports annually to Congress on the funds’ financial operations and actuarial outlook. ^[3]

Income and reserves

The program’s principal revenue source is payroll taxes paid by covered workers and employers, with self-employed workers paying the corresponding combined contribution. Other dedicated income includes federal income taxes on a portion of some beneficiaries’ Social Security benefits and interest earned on trust fund investments. The balance between the funds’ income and their costs determines whether reserves grow or decline in a given period. ^[4][5]

When dedicated income exceeds current program costs, the excess is credited to the trust funds and invested in U.S. government obligations. When costs exceed income, securities can be redeemed to provide resources for benefit payments and administrative expenses. Thus, reserves are accumulated holdings available to meet program costs when current income is insufficient. The annual Trustees Report describes historical operations and projects future income, costs, and reserves using demographic and economic assumptions. ^[2][5]

The trust funds’ securities are federal obligations, not private-sector assets such as stocks or corporate bonds. The law generally requires Social Security tax receipts credited to the funds to be invested in special, nonmarketable U.S. Treasury securities issued for the trust funds. These securities are not available for purchase by the general public. The Treasury may hold or issue marketable federal securities for the funds when authorized conditions apply, but the funds currently hold special issues. ^[5][6]

The accounting entries should be distinguished from the movement of cash within the federal government. Tax receipts exchanged for Treasury obligations are deposited in the Treasury’s General Fund and are not held in a separate vault for Social Security. The securities record the Treasury’s obligation to the trust funds. When the program needs to pay benefits, Treasury makes payments from the General Fund and redeems an equivalent amount of trust fund securities. Redemption reduces the recorded reserves and requires the Treasury to obtain cash through its overall financing and cash-management operations. ^[5]

OASI, DI, and combined projections

Trustees Reports may show OASI and DI separately or present a combined OASDI projection to illustrate the program’s overall position. The combined presentation is a hypothetical analytical measure: the funds remain legally separate, and they cannot simply be combined or freely transfer reserves between one another without a change in law. A combined projection therefore does not mean that reserves in one fund are automatically available to pay obligations assigned to the other. ^[4][citation needed]

The 2026 Trustees Report projected that OASI reserves would be able to pay 100% of scheduled benefits through the fourth quarter of 2032. After projected reserve depletion, continuing income to OASI was estimated to cover 78% of scheduled benefits. The report projected that the DI fund could pay 100% of scheduled benefits through at least 2100, the final year of its projection period. ^[4]

On the hypothetical combined basis, the report projected full payment of scheduled OASDI benefits through the third quarter of 2034. At that point, combined reserves were projected to be depleted, while continuing combined income was estimated to cover 83% of scheduled benefits. This combined date and percentage are actuarial projections under the Trustees’ assumptions, not a prediction that benefit payments would necessarily stop or that Congress would take no action. The report evaluates the financing outlook under current law and stated assumptions; changes in law or economic and demographic experience can affect later estimates. ^[4]

Meaning of reserve depletion

In Trustees Reports, “reserve depletion” means that a fund’s accumulated reserves are projected to reach zero. It does not mean that the program has no ongoing income. Payroll taxes and other dedicated revenues would continue to arrive, and those receipts could finance a portion of scheduled benefits. Under the 2026 combined projection, continuing income after reserve depletion would cover 83% of scheduled benefits. The shortfall between scheduled benefits and projected income would require legislative action to address if the law and projections otherwise remained unchanged. ^[4]

Projected depletion dates are estimates, not fixed deadlines. Trustees use assumptions about factors such as employment, wages, birth rates, mortality, productivity, inflation, and interest rates to estimate revenue and costs over a long horizon. The 2026 report’s long-range projection covers 2026–2100. New data, economic outcomes, demographic developments, and legislation can alter projections in future reports. Consequently, a depletion date should be read alongside its report year, assumptions, and the distinction between scheduled benefits and benefits supportable from continuing income. ^[7]

Reporting and terminology

The annual OASDI Trustees Report presents the separate funds’ operations, reserve balances, and short- and long-range estimates. Treasury supplies financial-operation and investment data, while the Social Security Administration’s actuarial office prepares projections and related analysis. The 2026 report recorded a decline in OASI reserves during calendar year 2025: income was $1,248.8 billion and cost was $1,448.8 billion, a $200.0 billion reduction. Such annual results are historical accounting figures; they are distinct from projections of future operations. ^[3][8]

The term “OASDI” refers to Old-Age, Survivors, and Disability Insurance, the Social Security programs financed through the OASI and DI trust funds. It should not be confused with Medicare’s Hospital Insurance and Supplementary Medical Insurance trust funds, which are reported separately and finance different health-insurance programs. Similarly, the Social Security trust funds are not the same as individual retirement savings plans: their balances are federal program reserves rather than participant-owned accounts. ^[1][4]

Related entries

The trust funds are associated with U.S. Department of the Treasury, which manages the accounts and issues the securities they hold, and Internal Revenue Service, which collects federal payroll taxes. Their projections also connect to 401(k) plan, a distinct form of employer-sponsored retirement saving, and to federal public debt recorded through Treasury obligations. ^[2][5]