My home country is Indonesia

I don't pay social security and medicare tax since I am on OPT and do not meet substantial presence test (4 years in USA).

But once I get my H1B approved in October, I will start paying social security tax and medicare (resident alien).

To sum it up:
Jan 08-Sept 08 - NOT paying social security and medicare tax (non resident alien on OPT)
Oct 08-Dec 08 - paying social security and medicare tax (resident alien on H1B)

What form do I use to file my taxes?? I am guessing it's only 1 form: the 1040 (for the resident?)

Please advise. Thank you so much!

If you did not complete 5 years on F1/OPT, then you will file nonresident tax return and Form 8843.

ok, I see so I will still use 1040NR for next year after I get my H1B visa.

Oh, I work full time now 40h on OPT, but I also pick up more hours 8 more hours every week overtime.. is that ok or is it illegal to do that?

I am thinking of working 2 jobs also to get extra money >_>

I appreciate your answer mukata! thanks!

Overtime is fine in your approved OPT job.

It is when you get a second, unapproved job that you can get into trouble for violating your visa provisions.

What about working 2 jobs on OPT > 40 hours (around 60 hours)?

Is that considered unapproved? Since OPT doesn't say I am bound to 1 employer. Both jobs related to my major of study. Basically, I am working in the pharmacy as a pharmacist.

Thanks!

This is tax forum. As far as IRS is concerned, you must report all your income. IRS is not concerned with visa requirements in such cases.