Here is where to buy and download TurboTax 2018 software: https://turbotax.intuit.com/personal-taxes/cd-download/
If you have a .tax 2018 tax return, how did you get it? Did someone else do your tax return for you? If you also have a pdf file of your 2018 tax return, you don't need the TurboTax program to open it.
