I am on H1b visa, I was in OPT on F1 visa from Feb 2010 to Sep 2010. The employer did not withhold FICA tax from my pay during that time. I thought that it is supposed to be for an F1 visa holder.
I just realize that I have been considered as a resident alien for federal tax purpose in that time. What I should do now, inform the payroll agent of the employer and get a new W-2 form? Thank you

Make sure that you are paying FICA taxes during H1-B period. For F1 or OPT period, you can not pay FICA taxes yourself.

Thank you for the information.

I have been using form 1040 for federal tax return since 2008. I was just told that as a resident alien for tax purpose has to pay FICA in opt.
So for F1, even resident aliens do not have to pay FICA? Thank you.

I have been using form 1040 for federal tax return since 2008. I was just told that as a resident alien for tax purpose has to pay FICA in opt.
So for F1, even resident aliens do not have to pay FICA? Thank you.