If your loan meets the following IRS requirements, you can deduct the interest.
https://www.irs.gov/publications/p970/ch04.html#en_US_2015_publink1000178237
Qualified Student Loan:
This is a loan you took out solely to pay qualified education expenses (defined later) that were:
For you, your spouse, or a person who was your dependent when you took out the loan;
Paid or incurred within a reasonable period of time before or after you took out the loan; and
For education provided during an academic period for an eligible student.
Loans from the following sources aren't qualified student loans.