Mac system requirements :
2018 Requires 10.12 or higher.
2019 will require 10.13 or higher.
You can use the ONLINE version instead ... and get a refund for the program you cannot use ...
You can go here TurboTax CD/Download Refund Request Form to request a refund if still within 60 days of purchase.
https://support.turbotax.intuit.com/forms/refund-request.jsp
