To prepare a 2017 return at this point in time you have to use the 2017 desktop
software (CD/download.) Online TurboTax is currently only for 2018 returns.
You can purchase 2017 desktop software as a download at this page and install it on your computer:
Minimum system requirements for Windows version:
Minimum system requirements for Mac version:
Or did you already start a 2017 return online prior to the 2017 online shutdown, and want to finish that without starting over? If so, you can download the *.tax2017 data file from your account and finish it in the desktop software. If you already paid for your product previously, TurboTax Support should furnish you the software.
The 2017 return cannot be efiled. It will need to be printed, signed, dated, and mailed. It is recommended to mail by a method that has tracking such as certified return receipt, priority mail, etc.
If you have both Federal and state returns, you need to mail each one separately to its respective tax agency.
If you are due a Federal refund, it takes about 6 weeks for the IRS to process a mailed return.