You cannot use TurboTax Online to file for a past year. TurboTax Online is only for the current tax year, which is now 2016. To file for an earlier year you have to use the CD or download TurboTax software for the year that you need to file. You can purchase a download for 2013, 2014, or 2015 at the following link.
http://turbotax.intuit.com/personal-taxes/past-years-products.jsp
You might get a better price from a reputable online seller that still has TurboTax in stock for the year that you need.
TurboTax does not allow returns for past years to be e-filed. You will have to print your past-year tax return and file it by mail.