The Social Security and Medicare taxes are collectively known as FICA (the Federal Insurance Contributions Act). Different rates apply for each of these taxes.
The current FICA tax rate is 7.65%, broken down as follows:
Social Security
Social Security tax rates are withheld at a flat 6.2% each for the employee and employer.
Reference the wage base limit for the current year's amount. This represents the maximum wage subject to that calendar year's tax.
Medicare
Withheld at a flat rate of 1.45% each for the employee and employer per the Social Security and Medicare tax rates website.
There is no wage base limit for Medicare tax. All covered wages are subject to Medicare tax.
.9% applied on wages over $200,000 based on the taxpayer's filing status.
View this FAQ to learn about exemptions from FICA withholding.