Hello everyone.
I have a question about Medical and social security taxes. I am an F1 visa holder. I have graduated from the University in the USA and receive OPT after that. I work for US company on my major. I have sent them all documents (copy F1 visa, work athorization and letter from the University I graduated). They keep teeling me that I can't work more then 20 hours and on campus only. I have tols them it is in case when I am inrolled in the Univarsity, but I am graduate student. I also sent them link form IRS.org about tax exeption. No results yet. Seems like they don't understand or don't want to deal with it. Could someone tell me how I can resolve it?

If you are on F-1 and work OP{T in your field of study, you are still considered to be a student and are exempt from both Social Security and Medicare taxes.

If the employer is withholding these taxes, request that they be refunded. Use IRS Pub 519, page 46 as your reference. If they refuse (quite likely), get the refusal in writing, then submit Form 843 to request a refund of these taxes.