The online version of TurboTax is only for the current tax filing year. The current tax filing year is for tax year 2018 and that's it. That will expire on or about Oct 15, 2019.
To complete a prior year tax return you have no choice but to purchase and install the CD version on your Windows or Mac computer. You can purchase it at https://turbotax.intuit.com/personal-taxes/past-years-products/
*MAKE* *SURE* you are under the correct tab for the tax year you need. If you purchase the product for the wrong tax year, you own it.
After you pay for it, you can download the installation file to your computer. After you download it, exit all programs and then double-click on the downloaded file to install it on your computer.
If on a MAC, drag the downloaded file to your Applications folder to install it.
