Social Security Explained | Civics Authority

Social Security is the largest single program in the federal budget and the primary source of retirement income for most Americans. Established by the Social Security Act of 1935 and expanded through decades of legislation, the program provides monthly cash benefits to retired workers and their families, to workers who become disabled, and to the survivors of deceased workers. A separate program, Supplemental Security Income, provides means-tested cash assistance to aged, blind, and disabled individuals with limited income and resources. Together, these programs serve more than 70 million Americans and represent the nation's most significant commitment to preventing poverty among the elderly and disabled. This page covers the program's history, structure, financing, benefit calculation, and the policy challenges it faces.

History and Origins

The Social Security Act was signed into law by President Franklin D. Roosevelt on August 14, 1935, during the Great Depression. The Act created a social insurance program funded by payroll taxes, under which workers would earn benefit entitlements through their employment history rather than receiving welfare based on need. This contributory structure was a deliberate design choice. Roosevelt insisted that the program be funded through dedicated payroll taxes rather than general revenues, famously explaining: "We put those payroll contributions there so as to give the contributors a legal, moral, and political right to collect their pensions. With those taxes in there, no damn politician can ever scrap my social security program."

The original program covered only retired workers in commerce and industry, excluding agricultural workers, domestic servants, the self-employed, and many other groups — exclusions that disproportionately affected African Americans and women. Coverage was gradually expanded through subsequent legislation: the 1950 amendments brought in self-employed workers, domestic workers, and agricultural workers; the 1956 amendments added disability insurance benefits; the 1965 amendments created Medicare; and the 1972 amendments established Supplemental Security Income and indexed benefits to inflation through automatic cost-of-living adjustments.

The constitutionality of Social Security was upheld by the Supreme Court in Helvering v. Davis, 301 U.S. 619 (1937), which held that the payroll tax was a valid exercise of Congress's taxing power and that the spending program served the general welfare. In Flemming v. Nestor, 363 U.S. 603 (1960), the Court held that individuals do not have an accrued property right in Social Security benefits and that Congress retains the authority to modify the benefit structure.

Program Structure

Social Security encompasses several distinct programs, each serving a different population and funded through different mechanisms.

Old-Age and Survivors Insurance (OASI)

OASI is the retirement and survivors benefit program — what most people mean when they refer to "Social Security." It provides monthly benefits to retired workers who have earned sufficient work credits, to spouses and dependent children of retired workers, and to survivors of deceased workers including widows, widowers, and dependent children. To qualify for retirement benefits, a worker must have earned at least 40 work credits (generally equivalent to ten years of covered employment). The amount of the monthly benefit depends on the worker's lifetime earnings history and the age at which benefits are claimed.

Social Security Disability Insurance (SSDI)

SSDI provides monthly benefits to workers who become unable to engage in substantial gainful activity due to a medically determinable physical or mental impairment that is expected to last at least 12 months or result in death. Eligibility requires that the worker have earned a sufficient number of work credits based on age at the onset of disability. SSDI uses a five-step sequential evaluation process to determine disability: (1) whether the claimant is engaged in substantial gainful activity; (2) whether the claimant has a severe impairment; (3) whether the impairment meets or equals a listed impairment in the Social Security Administration's regulatory listing of impairments; (4) whether the claimant can perform past relevant work; and (5) whether the claimant can perform any other work that exists in significant numbers in the national economy. SSDI recipients become eligible for Medicare after a 24-month waiting period.

Supplemental Security Income (SSI)

SSI is a means-tested program that provides monthly cash assistance to aged (65 and older), blind, and disabled individuals with limited income and resources. Unlike OASI and SSDI, SSI is not funded through payroll taxes but through general federal revenues. SSI eligibility is based on financial need rather than work history. The federal SSI benefit rate is set annually; many states supplement the federal benefit with additional state payments. SSI recipients are generally automatically eligible for Medicaid. The program serves approximately 7.5 million recipients, most of whom are disabled adults under age 65.

Financing and Trust Funds

Social Security is financed primarily through the Federal Insurance Contributions Act (FICA) payroll tax. Employers and employees each pay 6.2 percent of covered wages up to the taxable maximum ($168,600 in 2024), for a combined rate of 12.4 percent. Self-employed individuals pay the full 12.4 percent through the Self-Employment Contributions Act (SECA) tax. An additional 0.9 percent Medicare Hospital Insurance tax applies to wages above $200,000 for individuals ($250,000 for married couples filing jointly), but this tax funds Medicare, not Social Security.

Payroll tax revenues are deposited into two trust funds: the Old-Age and Survivors Insurance Trust Fund and the Disability Insurance Trust Fund. These trust funds hold special-issue Treasury securities — essentially IOUs from the federal government. When Social Security tax revenues exceed benefit payments, the surplus is invested in these securities, and the Treasury uses the cash for general government operations. When benefit payments exceed tax revenues — as has been the case since 2021 for the combined trust funds — the trust funds redeem securities to make up the difference, and the Treasury must raise the cash through general borrowing or other means.

In addition to payroll tax revenue, the trust funds receive income from two other sources: the taxation of Social Security benefits (individuals with combined income above certain thresholds pay federal income tax on up to 85 percent of their benefits, with the revenue directed to the trust funds) and interest earned on the trust fund securities.

Benefit Calculation

Social Security retirement benefits are calculated through a multi-step process designed to provide higher replacement rates for lower-earning workers while maintaining a relationship between earnings and benefits.

The first step is to determine the worker's Average Indexed Monthly Earnings (AIME). The Social Security Administration adjusts the worker's annual earnings for each year of covered employment to account for wage growth, selects the 35 highest-earning years, sums them, and divides by 420 (the number of months in 35 years). Workers with fewer than 35 years of covered employment have zeros averaged in for the missing years, reducing their AIME and, consequently, their benefit.

The AIME is then converted to the Primary Insurance Amount (PIA) using a progressive benefit formula with two "bend points" that are adjusted annually for wage growth. The formula replaces 90 percent of the first portion of AIME (up to the first bend point), 32 percent of AIME between the first and second bend points, and 15 percent of AIME above the second bend point. This progressive structure means that lower-earning workers receive a higher percentage of their pre-retirement earnings in benefits, though higher-earning workers receive larger absolute benefit amounts.

The PIA represents the benefit amount the worker would receive at full retirement age (FRA). Workers who claim benefits before FRA receive a permanently reduced benefit; those who delay claiming beyond FRA receive delayed retirement credits that increase the benefit up to age 70. The reduction for early claiming is 5/9 of one percent per month for the first 36 months before FRA and 5/12 of one percent per month for each additional month. Delayed retirement credits increase the benefit by 8 percent per year for each year benefits are delayed beyond FRA up to age 70.

Full Retirement Age

Full retirement age is the age at which a worker is entitled to receive unreduced retirement benefits. Under the 1983 amendments, FRA was gradually increased from 65 to 67. Workers born in 1937 or earlier have an FRA of 65. FRA increases by two months per birth year for those born 1938 through 1943, reaching 66 for those born in 1943 through 1954. FRA then increases by two months per birth year for those born 1955 through 1960, reaching 67 for those born in 1960 or later. The earliest age at which retirement benefits can be claimed is 62, but claiming at 62 results in a permanently reduced benefit — approximately 30 percent less than the full benefit for workers with an FRA of 67.

Cost-of-Living Adjustments

Social Security benefits are adjusted annually to keep pace with inflation through cost-of-living adjustments (COLAs). The COLA is based on the percentage increase in the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W) from the third quarter of the prior year to the third quarter of the current year. If there is no increase in the CPI-W, there is no COLA. COLAs have ranged from zero (in 2010, 2011, and 2016) to 8.7 percent (in 2023, reflecting the high inflation of 2022). The adequacy of the CPI-W as a measure of inflation experienced by retirees has been debated, with some advocates arguing that an index specifically designed to measure the spending patterns of the elderly — such as the experimental CPI-E — would more accurately reflect the higher health care costs that consume a larger share of retirees' budgets.

Solvency Projections

The Social Security Board of Trustees issues an annual report projecting the financial status of the trust funds over a 75-year horizon. The 2024 Trustees Report projected that the combined OASI and DI trust funds will be depleted in 2035 under the intermediate assumptions. Upon depletion, incoming payroll tax revenue would be sufficient to pay approximately 83 percent of scheduled benefits. The OASI Trust Fund alone is projected to be depleted in 2033, at which point revenues would cover approximately 79 percent of scheduled benefits.

The primary driver of the projected shortfall is demographic: the ratio of workers paying into the system to beneficiaries drawing from it is declining as the baby boom generation retires and life expectancy increases. In 1960, there were approximately 5.1 workers per beneficiary; today, the ratio is approximately 2.8 workers per beneficiary, and it is projected to decline to approximately 2.3 by 2040. Rising health care costs, slower productivity growth, and increasing income inequality (which causes a growing share of earnings to fall above the taxable maximum) also contribute to the financing gap.

Trust fund depletion would not mean the end of Social Security. The program is primarily a pay-as-you-go system, and incoming payroll taxes would continue to fund the majority of scheduled benefits indefinitely. However, under current law, the Social Security Administration lacks authority to pay benefits in excess of the amounts available in the trust funds, meaning that benefits would need to be reduced to match available revenue absent legislative action.

Spousal, Survivor, and Dependent Benefits

Social Security provides benefits not only to retired and disabled workers but also to their family members. A spouse who has reached age 62 (or who cares for a child under 16 or a disabled child) may receive a spousal benefit equal to up to 50 percent of the worker's PIA. A divorced spouse who was married to the worker for at least ten years and has not remarried may also claim spousal benefits on the former spouse's record. When a worker dies, the surviving spouse may receive survivor benefits equal to 100 percent of the deceased worker's benefit if the surviving spouse has reached full retirement age (with actuarial reductions for earlier claiming). Dependent children under 18 (or under 19 if still in high school) may receive benefits on a retired, disabled, or deceased parent's record. A maximum family benefit applies, limiting the total benefits payable on a single worker's record to between 150 and 188 percent of the worker's PIA.

The interaction between spousal benefits and a worker's own retirement benefits creates a complex set of claiming strategies. A spouse entitled to both a worker benefit on their own record and a spousal benefit on their partner's record receives the higher of the two amounts (not both). The Social Security Administration calculates the benefit both ways and pays the larger amount. The Bipartisan Budget Act of 2015 eliminated certain claiming strategies — including "file and suspend" and "restricted application" — that had allowed married couples to maximize their combined lifetime benefits through strategic timing of their claims.

Administration and Appeals

The Social Security Administration (SSA) is an independent federal agency that administers Social Security and SSI programs. SSA operates approximately 1,200 field offices across the country, processes approximately 6 million claims for retirement, survivors, and disability benefits annually, and maintains earnings records for approximately 175 million workers. SSA is also responsible for issuing Social Security numbers, which serve as the primary individual identifier for tax, employment, and government benefits purposes.

Individuals who are denied benefits or who disagree with an SSA determination have the right to a multi-stage administrative appeals process. The first level is reconsideration — a review of the initial decision by a different SSA examiner. If denied at reconsideration, the claimant may request a hearing before an Administrative Law Judge (ALJ), who conducts a de novo review including the opportunity for the claimant to appear and present evidence. ALJ decisions may be appealed to the Appeals Council, which may grant, deny, or dismiss the request for review. After exhausting administrative remedies, the claimant may seek judicial review in federal district court under 42 U.S.C. section 405(g). The appeals process is particularly significant in disability cases, where the initial denial rate has historically exceeded 60 percent but a substantial number of claims are approved on appeal, particularly at the ALJ hearing stage.

Reform Proposals

Proposals to address Social Security's long-term financing shortfall generally fall into three categories: revenue increases, benefit reductions, and structural changes.

Revenue proposals include raising or eliminating the taxable maximum so that higher earners pay FICA taxes on a larger share of their income; increasing the payroll tax rate; dedicating new revenue sources (such as investment income taxes) to the trust funds; and expanding coverage to include state and local government employees who are currently exempt. Raising the taxable maximum to cover 90 percent of covered earnings — the level Congress intended when it last adjusted the cap in 1983 — would close a significant portion of the projected shortfall.

Benefit reduction proposals include further increasing the full retirement age to reflect gains in life expectancy; adopting a less generous COLA formula, such as the chained CPI, which accounts for consumer substitution behavior and grows more slowly than the CPI-W; modifying the benefit formula to reduce benefits for higher earners while protecting lower earners; and means-testing benefits so that wealthier retirees receive reduced payments.

Structural proposals include partially privatizing Social Security by allowing workers to divert a portion of their payroll taxes into individual investment accounts — an approach advocated by President George W. Bush in 2005 but rejected by Congress — and converting the system from defined-benefit to defined-contribution. These proposals have been controversial because they would fundamentally alter the social insurance character of the program and would expose individual workers to investment risk.

No reform package has achieved the political consensus necessary for enactment. The difficulty is structural: any combination of revenue increases and benefit reductions sufficient to close the long-term financing gap requires choices that impose costs on either current workers, current retirees, or both. The longer legislative action is delayed, the larger the eventual adjustments will need to be, as each year of inaction increases the accumulated shortfall. Social Security's financing challenge is not a crisis of design but a consequence of demographic changes that the original program was not structured to accommodate, and addressing it requires the same kind of bipartisan compromise that produced the successful 1983 reforms.