The employer's Social Security tax rate for 2015 is 6.2% of each employee's first $118,500 of wages, salaries, etc. If an employee has wages, salaries, etc. that are greater than $118,500, the amount in excess of $118,500 is not subject to the Social Security tax. Hence, the maximum amount of the employer's Social Security tax for each employee in 2015 is $7,347 (6.2% X $118,500).

The employer's Social Security tax is in addition to the employee's Social Security tax.

In addition to the employer's Social Security tax, there is also an employer's Medicare tax of 1.45%. The Medicare tax applies to every dollar of every employee's wages, salaries, etc. In other words, there is no wage limit or cap for the employer's Medicare tax.