@daviddmayes
Oops! The answer above originally had some references to 2017 software by mistake. It was pasted from another of my answers, and I didn't get all the years changed in the post. I noticed it right away and have corrected it with the correct tax years above. Sorry about any confusion! Please return to the forum to see the corrected answer with the full info.
A 2015 return requires 2015 desktop software. See the additional info in the answer above.
Also, if you are due a 2015 Federal tax refund, while you can still file the return, the deadline to claim a 2015 Federal refund was April 15, 2019, unless you originally filed for an extension back in 2015.
