You can - but you must also have paid the student loan in addition to be legally obligated to pay it back (and your are as a co-signer) to be able to deduct it's interest. And if you did pay, the data entry is as follows:
- Federal Taxes
- Deductions & Credits
- Education
- Select Student Loan Interest Paid (Form 1098-E) - follow the prompts
The issue may arise if 1098-E is not in your name. However, if
you ever receive a letter from the IRS to "prove" that you were
obligated to pay the loan, you can simply send them a copy of the loan
with your name on it.
