You can deduct student loan interest if:
You paid
interest on a qualified student loan in tax year 2015
You are legally obligated to pay interest (ie. you are a co-signer) on a
qualified student loan
Your are not filing Married Filing Separate
Your Modified Adjusted Gross Income is less
than a specified amount which is set annually, and
You or your spouse, if filing jointly,
cannot be claimed as dependents on someone else's return.
If you
are not legally liable for the loan, you cannot claim student loan interest
If
the named borrower qualifies per the above rules, he/she can claim the interest