我是八月2003到美,暑假没注课, RA, 同样的问题, 下面是b office给我的回信, the additional withholdings are Social Security ($108.26) and Medicare ($25 .32) which is about 7.64% of your gross income. These are withheld when a student is not presently enrolled. I am assuming you are not enrolled for the summer or you were not yet enrolled when this payroll was processed. The second factor is that you have been here sine 2003. XX payroll counts that as Year 1 making 2007 Year 5. After 5 years, a foreign citizen is subje