You can no longer do a tax return earlier than 2016 using TurboTax. You can do 2017 and 2018 on separate tax returns by buying, downloading and installing on your computer the tax program for each tax year. Here is link to buy them: https://turbotax.intuit.com/personal-taxes/past-years-products/
Prior year returns must be printed and mailed by you. They can't be efiled and TurboTax does not mail them for you.
To do a tax return earlier than 2016, you would have to go to a paid preparer or manually complete them using forms from the IRS. Here is where you can download them:
The IRS will not longer pay a refund on any tax returns prior to 2016. You only have until July 15, 2020 to file a 2016 return and get a refund. The filing deadline for a refund is 3 years from the original filing date except for 2016 which has been extended to July 15. You must still file tax returns for earlier years or face continued penalties and interest from the IRS.
