Social Security Tax

Social Security tax is the 6.2% payroll tax withheld from wages to fund retirement, survivor and disability benefits. It applies only up to the Social Security wage base, which usually rises each year. Employers pay the same amount again.

Pay stubs often label it OASDI, short for the program's official name. See OASDI and what OASDI on a paycheck means. On a $2,307.69 paycheck it comes to $143.08.

It is one half of FICA, and Medicare tax is the other. Once your pay for the year passes the wage base, it stops until January. If you work two jobs, each employer withholds up to the wage base, and any extra comes back as a credit on your federal return. The FICA tax guide covers the cap.