I would like to do my 2017 taxes on turbo tax, why do i have to purchase the program?

[Critter]

Because the ONLINE version is closed for 2017  in preparation for the 2018 tax season coming up.  All 2017 returns must be mailed in now and the downloaded version needs to be used. 

[xmasbaby0]

In order to prepare and file a 2017 return you now have to purchase and download the desktop software to a full PC or Mac--not a mobile device--then print, sign and mail it. Online preparation and e-filing are permanently closed for 2017 returns.

https://turbotax.intuit.com/personal-taxes/past-years-products/

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS and/or your state received the return.