Student loans are not taxable in the U.S.

If you are a college student and you need to file a U.S. tax return, take note. As far as I can tell, student loans are not taxable!

Student loans are also not taxable. If all or part of a student loan is cancelled or forgiven, the amount of debt forgiven may represent taxable income. See IRC section 108(f) for details.
- http://www.finaid.org/scholarships/taxability.phtml

4.8 Interest, Dividends, Other Types of Income: Grants, Scholarships, Student Loans, Work Study

Is money from student loans considered taxable income?

A school loan is not taxable at the time you get the money and should not be included as income on your return. A loan is not income because you are expected to repay the amount borrowed (plus interest). If, at a later date, any part of the loan is forgiven, the amount forgiven would be income in that year. Under certain circumstances, student loans forgiven are not income. For more information, refer to Exceptions under Canceled Debts in Publication 525 (PDF), Taxable and Nontaxable Income.

References:

* Publication 525 (PDF), Taxable and Nontaxable Income
* Tax Topic 422, Nontaxable income

- http://www.student-loans.net/student-tax-faq.htm

However, I could not find a conclusive answer on the IRS website. So if you happen to know more about this, please post a comment.