Will I be able to use TurboTax 2020 on my iMac with High Sierra OS, version 10.13.6?

[VolvoGirl]

@kolbrh   If you have been using the Desktop program here's some things to know about switching to the Online version.

If you used the Desktop program last year here’s How to transfer into the Online version, expand the blue link if you used the CD/download last year........

https://ttlc.intuit.com/community/entering-importing/help/how-do-i-transfer-last-year-s-return-into-...

If you used the Desktop program before you may not like the online version.  It has less features and no Forms Mode.  You can only do 1 return.  Your return is only saved online so be sure to save both the .tax2021 data file and the pdf file to your computer when you are done.  In case you need to amend in the future or if you need a copy to get a loan or something.  You might not be able to access your online return when you need a copy.