“Social Security is the federal government’s largest single program. Of the 59 million people who currently receive Social Security benefits, about 71 percent are retired workers or their spouses and children, and another 10 percent are survivors of deceased workers; all of those beneficiaries receive payments through Old-Age and Survivors Insurance (OASI). The other 19 percent of beneficiaries are disabled workers or their spouses and children; they receive Disability Insurance (DI) benefits. In fiscal year 2014, spending for Social Security benefits totaled $840 billion, or almost one-quarter of federal spending; OASI payments accounted for about 83 percent of those outlays, and DI payments made up about 17 percent. Each year, CBO prepares long-term projections of revenues and outlays for the program. The most recent set of 75-year projections was published in July 2014. Those projections generally reflect current law, following CBO’s 10-year baseline budget projections through 2024 and then extending the baseline concept for the rest of the long-term projection period. This publication presents additional information about those projections. Social Security has two primary sources of tax revenues: payroll taxes and income taxes on benefits. About 97 percent of those revenues derive from a payroll tax—generally, 12.4 percent of earnings—that is split evenly between workers and their employers; self-employed people pay the entire tax. The payroll tax applies only to taxable earnings—earnings up to a maximum annual amount ($117,000 in 2014). The remaining share of tax revenues—3 percent—is collected from income taxes that higher-income beneficiaries pay on their benefits. Tax revenues credited to the program totaled $777 billion in fiscal year 2014. Those tax revenues are credited to Social Security’s two trust funds—one for OASI and one for DI—along with intragovernmental interest payments on the Treasury securities held by those funds. In turn, the program’s benefits and administrative costs are paid from those funds. Although legally separate, the funds often are described collectively as the OASDI trust funds. In a given year, the sum of receipts to each of the funds, along with the interest that is credited on balances, minus spending for benefits and administrative costs, constitutes that fund’s surplus or deficit. In calendar year 2010, for the first time since the enactment of the Social Security Amendments of 1983, annual outlays for the program exceeded annual tax revenues (that is, outlays exceeded totalrevenues excluding interest credited to the trust funds). In 2013, outlays exceeded noninterest income by about 9 percent, and CBO projects that the gap will average about 17 percent of tax revenues over the next decade. As more members of the baby-boom generation retire, outlays will increase relative to the size of the economy, whereas tax revenues will remain at an almost constant share of the economy. As a result, the gap will grow larger in the 2020s and will exceed 30 percent of revenues by the late 2020s. CBO projects that under current law, the DI trust fund will be exhausted in fiscal year 2017, and the OASI trust fund will be exhausted in 2032. If a trust fund’s balance fell to zero and current revenues were insufficient to cover the benefits specified in law, the Social Security Administration would no longer have legal authority to pay full benefits when they were due. In 1994, legislation redirected revenues from the OASI trust fund to prevent the imminent exhaustion of the DI trust fund. In part because of that experience, it is a common analytical convention to consider the DI and OASI trust funds as combined. Thus, CBO projects, if some future legislation shifted resources from the OASI trust fund to the DI trust fund, the combined OASDI trust funds would be exhausted in 2030. The amount of Social Security taxes paid by various groups of people differs, as do the benefits that different groups receive. For example, people with higher earnings pay more in Social Security payroll taxes than do lower-earning participants, and they also receive benefits that are larger (although not proportionately so). Because Social Security’s benefit formula is progressive, replacement rates—annual benefits as a percentage of average annual lifetime earnings—are lower, on average, for workers who have had higher earnings. As another example, the amount of taxes paid and benefits received will be greater for people who were born more recently because they typically will have higher earnings over a lifetime, even after an adjustment for inflation, CBO projects.”