The Social Security program in the United States provides protection against the loss of earnings due to retirement, death, or disability. The financial operations of this program are handled through the Old-Age and Survivors Insurance (OASI) and Disability Insurance (DI) Trust Funds.

Monthly benefits are paid from the OASI Trust Fund to retired workers and their families and to survivors of deceased workers. Monthly benefits are paid from the DI Trust Fund to disabled workers and their families.

Both funds are financed primarily by contributions, or taxes, paid by employees, their employers, and self-employed persons. Other sources of income are interest on investments and income from the taxation of benefits.