With few exceptions, companies subject to Medicare are also subject to social security. Because of this guideline, QuickBooks marks both the Medicare and the social security options in the employee record.
If your company is subject to one tax and not the other, you can correctly set the options in the employee record by clicking Continue in the message that appears. When should an employee be marked as exempt from a tax?
To find out how this setup affects your payroll taxes, consult your professional tax advisor.