how can we get high Sierra version 10.14 ... it is not listed in the App store... my MacBook air has macOS high sierra v.10.13.6
The 10.14 is Mac Mojave, not Sierra. You can view the Turbo Tax system requirements here to get further clarification on the system requirements.
Thank you very much for your help.
I upgraded the MacBook Air from macOS High Sierra 10.13.6 to macOS Big Sur version 11.1 and successfully installed and ran 2020 Turbo Tax.
My IMAC is a 2011 system. The highest level it can go is High Sierra 10.13.6. What options do I have to use Turbo Tax 2020. Are you saying I have to buy a new MAC?
The system requirements for each year has been provided for you by clicking here.