基数就是你每张paycheck的毛收入。请来懂的给你画个图示：

以下知识是告诉老板们如何从员工的工资里扣除员工的FICA税及他们要如何match的部分。

How much is Medicare tax?

The Medicare tax percentage is 1.45% in 2017. Withhold 1.45% of each employee’s wages, and contribute the matching employer portion. Medicare taxes provide aid for things like healthcare and hospice care.

Let’s look at an example of how much is taken out for Medicare. Your employee is paid $1,000 per pay period. You would withhold $14.50 from their pay for Medicare tax ($1,000 X 1.45%). Also, contribute $14.50 for the matching employer portion.

详细请阅读：

https://www.patriotsoftware.com/payroll/training/blog/much-need-take-employees-paycheck/