If you want to input the 2015 return you will have to buy & install the 2015 downloaded program which can be bought here : https://turbotax.intuit.com/personal-taxes/past-years-products/
Good news, if you get the 2015 return in and it matches the original, you can transfer in that info to the 2016 program ... so don't start a 2016 program until you finish the 2015.
