Apple first released High Sierra on 25-Sep-2017 and continued to consider it a supported version until 1-Dec-2020. I downloaded TurboTax Premier 2020 on 17-Nov-2020, so High Sierra was an officially supported version of macOS at the time I received TurboTax Premier 2020 (although it was known that official support of High Sierra would end very soon thereafter). I find it disheartening that Intuit would fail to support a version of macOS that Apple released less than four years before the filing date for 2020 returns and that Apple supported at the time that TurboTax 2020 was released. This is an especially poor business decision since it was already known that the next version of macOS (Mojave) would not run on many older Macs and Apple had already announced a migration to Apple silicon, so many Mac users were waiting for the introduction of the full line of new Macs using Apple silicon to be available before buying a new Mac that would run a later version of macOS..
I don't have any realistic expectation of Intuit changing their mind now and releasing TurboTax 2020 that runs on High Sierra (or earlier versions of macOS). I just hope that Intuit learns its lesson and doesn't disrespect and abandon loyal customers this way in the future.
