How is Social Security Financed?

Social Security is financed through a dedicated payroll tax. Employers and employees each pay 6.2 percent of wages up to the taxable maximum of $118,500 (in 2015), while the self-employed pay 12.4 percent.

In 2013, $726 billion (85 percent) of total Old-Age and Survivors Insurance and Disability Insurance income came from payroll taxes. The remainder was provided by interest earnings ($103 billion or 12 percent) and revenue from taxation of OASDI benefits ($21.1 billion or 3 percent), and $4.9 billion in reimbursements from the General Fund of the Treasury - most resulting from the 2012 payroll tax legislation.

The payroll tax rates are set by law, and for OASI and DI, apply to earnings up to a certain amount. This amount, called the earnings base, rises as average wages increase.

Tax rates for employees and employers each under current law
Year OASI DI OASDI
2000 and later 5.30 0.90 6.20
SOURCE: 2013 OASDI Trustees Report