Federal tax withholding include social security and medicare

An employer's federal payroll tax responsibilities include withholding from an employee's compensation and paying an employer's contribution for Social Security and Medicare taxes under the Federal Insurance Contributions Act (FICA).

Employers have numerous payroll tax withholding and payment obligations. Of the utmost importance is the proper payment of what are commonly known as FICA taxes. FICA taxes are somewhat unique in that there is required withholding from an employee's wages as well as an employer's portion of the taxes that must be paid.

The Federal Insurance Contributions Act (FICA) is the federal law requiring you to withhold three separate taxes from the wages you pay your employees. FICA is comprised of the following taxes:

1. 6.2 percent Social Security tax;
2. 1.45 percent Medicare tax (the “regular” Medicare tax); and
3. Since 2013, a 0.9 percent Medicare surtax when the employee earns over $200,000.

You must withhold these amounts from an employee's wages.

The law also requires you to pay the employer's portion of two of these taxes:

• 6.2 percent Social Security tax
• 1.45 percent Medicare tax (the “regular” Medicare tax).

As you can see, the employer’s portion for the Social security tax and the regular Medicare tax is the same amount that you're required to withhold from your employees' wages. (Different rules apply for employees who receive tips.)  There is no employer portion for the 0.9 percent Medicare surtax on high-earning employees.

In other words, you withhold a 6.2 percent Social Security tax from your employee’s wages and you pay an additional 6.2 percent as your employer share of the tax (6.2 employee portion + 6.2 employer portion = 12.4 percent total). Also, you withhold a 1.45 percent Medicare tax from your employee’s wages and you pay an additional 1.45 percent as your employer share (1.45 employee portion + 1.45 employer portion = 2.9 percent total). The total of all four portions is 15.3 percent (6.2 percent employee portion of Social Security + 6.2 percent employer portion of Social Security + 1.45 percent employee portion of Medicare + 1.45 percent employer portion of Medicare = 15.3 percent).

Unlike the other FICA taxes, the 0.9 percent Medicare surtax is imposed on the employee portion only. There is no employer match for the Medicare surtax (also called the Additional Medicare Tax). You withhold this 0.9 percent tax from employee wages and you do not pay an employer’s portion. Also, unlike the other FICA taxes, you withhold the 0.9 percent Medicare surtax only to the extent that wages paid to an employee exceed $200,000 in a calendar year. You begin withholding the surtax in the pay period in which you pay wages in excess of this $200,000 “floor” to an employee and you continue to withhold it each pay period until the end of the calendar year.

Wage caps and floors

The Social Security tax (also called OASDI) is subject to a dollar limit, which is adjusted annually for inflation. However, there is no annual dollar limit for the 1.45 percent Medicare tax. Unlike the other FICA taxes, the 0.9 percent Medicare surtax is not withheld unless wages paid to an employee exceed $200,000.

Social security wage cap

For 2017, your obligation to withhold and to pay the Social Security tax for an employee ends once you've paid that employee total wages of $127,200. (For 2016, the amount is $118,500.)

Medicare wages

As there is no ceiling on the 1.45 percent portions of the Medicare tax, you must continue to withhold and to pay the Medicare tax regardless of how much you pay an employee.

Medicare surtax wage floor

You withhold the 0.9 percent Medicare surtax only to the extent you pay an employee wages in excess of $200,000 in a calendar year. You do not begin withholding the Medicare surtax until the pay period in which you pay wages in excess of $200,000 to an employee. There is no employer share: you withhold the 0.9 percent surtax from employee wages.

Example

Trevor, your employee, received $170,000 in wages from you through November 30, 2017. On December 1, 2017, you pay Trevor a $50,000 bonus. Prior to December 1, you were not required to withhold the Medicare tax surcharge. On December 1, you are required to withhold Additional Medicare Tax on $20,000 of the $50,000 bonus. You may not withhold Additional Medicare Tax on the other $30,000. You must also withhold the additional 0.9 percent Medicare tax on any other wages paid to Trevor in December 2017.

Calculating the withholding and employer's portion amounts

You simply multiply an employee's gross wage payment by the applicable tax rate to determine how much you must withhold and how much you must pay in Social Security and regular Medicare taxes.

The Social Security and regular Medicare taxes owed are unaffected by the number of withholding exemptions an employee may have claimed for income tax withholding purposes.

Calculating the medicare surtax withholding amount

Unlike the 6.2 percent Social Security tax and the 1.45 percent Medicare tax, the 0.9 percent surcharge is imposed only on the employee. You withhold the surtax from employee wages, but there is never a matching payment required by the employer.

The employer’s and employee’s obligations with respect to the Medicare surtax are different. In some cases, there may be a “mismatch” between the amounts you are obligated to withhold and the amount of your employee’s surtax liability.

From the employee’s perspective, the 0.9 percent Medicare surtax is imposed on wages, compensation and self-employment earnings above a threshold amount that is based on the employee’s filing status. Once the threshold is reached, the tax applies to all wages that are currently subject to Medicare tax, to the Railroad Retirement Tax Act or to the Self-Employment Compensation Act.

The threshold amounts are as follows: