基數就是你每張paycheck的毛收入。請來懂的給你畫個圖示：

以下知識是告訴老板們如何從員工的工資裏扣除員工的FICA稅及他們要如何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.

詳細請閱讀：

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