hi just wondering if you are doing an internship and on F1 status. do you need to pay social security tax and medicare tax?

yes..

No you dont need to pay SS tax and medicare tax. You just need to pay state tax and federal tax.

It is true F1 student are treated as Residence Alien and should not be withheld SS and Medicare.
It depends upon Univeristy to University, how they treat you?
I have seen Iowa State University not only withholding Federa, state, SS and medicare but also retirement fund.

(in that case 0nce s/he is out of school all retiement fund withheld was refunded. As per tax law such fund are treated as withdrawn and should be rollover within 3 month other wise not only treated as income, but also has to pay 10% for early withdrawal.)

Please read 10% penalty.

I am in CA. I just looked my first paycheck, they have withheld:
Federal Income TAx
Social Security Tax
medicare Tax
CA SUI/SDI tax?
Total Tax withheld is: almost 28%

No if you are just doing internship you don't have to pay any social security and medicare. Fill out this Form W-8ECI and give it to your employer (Human Resource or Payroll Department).This is a very easy form to fill and is available in the IRS website or just do google search.

Dude! I had a same problem, when I was doing my internship. They deducted SS(FICA) tax, then later I googled IRS webiste and found that people are in F-1 status are exempted from SS(FICA) and medicare tax. Reason! you are not going to get return benefit from it. You might want to google it and show that to your employer, human resources or auditor whoever responsible. I am 100% sure you don't need to pay those taxes, if you had paid already, ask them to refund or if they don't agree, then you can claim you tax(FICA) return while filing your tax return form. GOOD LUCK!

Guys
when you are doing your Internship or OPT you don't have to pay SST and MCT. You can visit the following website. If you are paying those tax talk to your Payroll department that you are in F1 and you don't have to pay sst and mct. or if they don't exempt you from paying that you can claim your tax while filing it. But You better talk to your payroll with strong opinion and provide them the following reference. they will try to refuse doing that I don't know why.
http://www.irs.gov/businesses/small/international/article/0,,id=131635,00.html

thanks guys. does that mean i have to fill form 8233 instead of W4 form

Guys you are exempt of SS tax till 5 calender years. After that you have to pay that.