County College of Morris is an equal opportunity and affirmative action institution and complies with Title IX, ADA and Civil Rights obligations. Quicklinks Academic Advisement
Determining Taxable Amount. If your base income exceeds the limit for your filing group, you'll have to pay taxes on some of your Social Security benefits. If you're a single filer and your base income is between $25,000 and $34,000, you'll have to pay tax on up to 50 percent of your Social Security benefits.
Calculate Social Security tax. The tax rate for Social Security is 12.40 percent of gross earnings, of which the employee pays half, or 6.20 percent. Multiply gross earnings by 6.20 percent to find the Social Security tax to be deducted from the employee's pay. Find the amount of Medicare tax.ocial Security taxes are levied on gross earnings before any deductions. Review the employee's year-to-date earnings. There is a cap on income subject to the Social Security tax (but not for the Medicare tax). As of 2009 the cap was $106,800.