Social Security (OASDI) Program Rates & Limits 2020; Tax Rates (percent) Social Security (Old-Age, Survivors, and Disability Insurance) Employers and Employees, each a: 6.20: Medicare (Hospital Insurance) Employers and Employees, each a,b: 1.45: Maximum Taxable Earnings (dollars) Social Security: 137,700: Medicare (Hospital Insurance) No limit 2020 Social Security and Medicare Tax Withholding Rates and Limits. For 2020, the maximum limit on earnings for withholding of Social Security (old-age, survivors, and disability insurance) tax is $137,700.00. The Social Security tax rate remains at 6.2 percent. The resulting maximum Social Security tax for 2020 is $8,537.40. Are Your 2020 Social Security Taxes Going Up? the payroll tax rate for Social Security has been 6.2%. Employees pay that amount, and employers pay another 6.2% out of their own pockets