To complete and file a 2017 and 2018 tax return using TurboTax you would need to purchase, download and install on a personal computer, Win or Mac, one of the desktop editions for each tax year from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
Prior year tax returns can only be printed and mailed, they cannot be e-filed. Use separate envelopes for each tax year.
