The current online product can only be used to prepare and file a 2019 tax return. To prepare a 2018 tax return you must buy, download and install on your computer the 2018 program. Here is a link to buy it: https://turbotax.intuit.com/personal-taxes/past-years-products/
Prior year returns can no longer be efiled. You must print and mail it yourself. TurboTax does not print and mail it for you. Use the instructions which will print with your return for what to include and where to mail your return. Make sure you sign and date it.
