All F-1 and J-1 students must file federal tax forms every year they are in the US even if they do not earn any money in the US. The deadlines to file the forms are April 15, if you have earned money in the US (including scholarships and assistantships), and June 15, if you have not earned money in the US.
Students earning money while in the US may have to pay federal and state income taxes. The completion of a W-4 form at the time of hire determines the amount of tax to be withheld from each paycheck.
International students in F status for 5 years or less (since 2002 or later) and their dependents, file tax forms as non-residents. If you did not earn any U.S. income during 2006 other than bank or credit union interest, then you need only file form 8843, Statement for Exempt Individuals and Individuals with a Medical Condition.
The purpose of the 8843 is to verify that the non-resident qualifies to exempt days of presence, and thus shields the non-resident from being taxed as resident. Being taxed as a U.S. resident allows the IRS to tax your world-wide income.
International students who have been in for F status for more than 5 years, or those who are in other non-immigrant statuses, are generally eligible to file as residents for tax purposes, and must use different forms.
Students often mistakenly claim "exempt" on this form only to find they must pay a large sum of tax on April 15. Students should only claim "exempt" if they are positive it will not negatively affect their tax liability.
Social Security Taxes
In general, F-1 students who have been in the U. S. less than five years are exempt from Social Security (F.I.C.A.) withholding. Further information may be found in a booklet entitled "Social Security Coverage for Foreign Students & Exchange Visitors" available from your local Social Security Administration office.
Federal, State, and Local Taxes
The earnings of F-1 students are subject to applicable federal, state, and local taxes, and these amounts should be withheld from paychecks. You must file an income tax return on or before April 15 of each year, which will determine if any of the withheld taxes can be reclaimed.