The TurboTax online editions are Only for tax year 2019.
To complete and file a prior year tax return (2016 thru 2018) using TurboTax you would need to purchase, download and install on a personal computer, Win or Mac, one of the desktop editions for each year needed from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A prior year tax return can only be printed and mailed, it cannot be e-filed. When mailing multiple tax years use separate envelopes for each tax year.
