I wasn't aware that I could claim student loan interest last year, can I still claim it this year?

[IreneS]

You can claim student loan interest paid in 2016 on your 2016 return.  You would have to amend your 2015 return to include the 2015 student loan interest.

To enter 2016 student loan interest in TurboTax, please follow these steps:

1. Click on Federal Taxes [Personal in TurboTax Self-Employed] > Deductions & Credits.
2. In the Education section, click on the Start/Revisit box next to Student Loan Interest Paid (Form 1098-E).
3. Enter the information requested on the screens.

Please see this FAQ for details on amending your 2015 return:  How to amend (change or correct) a return you already filed