@Solar Eclipse quick clarification from the thread below that "for desktop the current year and three prior years are supported" i.e. 4 latest versions. I was able to install and activate 2021 on my new Mac and open my old 2021 return.
I also tried 2020 just to check - I was able to install and activate it - but state would not install ("Hmm... it looks like we’ve hit a slight snag"), which prevents a .tax2020 with state filing from opening.
https://ttlc.intuit.com/community/taxes/discussion/re-why-can-t-i-find-the-basic-version-of-turbotax...
