A2: You've met the "substantial test" under the IRS rules and are considered as the Resident Alien for tax purpose. Therefore, you are no longer eligible for filing IRS form 843 to get your FICA taxes back.
Q9: 那如果OPT 时候被扣了FICA,但07想first year choice按residents报税,还用补f1时候没交的fica么?谢谢啦
A: No. And you should be able to the FICA during OPT back.
仔细读了,可是怎么感觉这两条矛盾呢?