Social Security payroll taxes are collected under the Federal Insurance Contributions Act (FICA) and the payroll taxes are sometimes referred to as “FICA taxes.” The payroll taxes collected for Social Security are taxes, but they are also contributions to the social insurance system that is Social Security.
More information about FICA taxes can be found on the SSA website.
The OIS Taxes section provides additional details on FICA Taxes and guidelines for international students and scholars.