The TurboTax 2018 software for a Mac requires OS X v.10.12 or later (64-bit required)
Go to this TurboTax website to request a refund for the software purchased from TurboTax - https://support.turbotax.intuit.com/forms/refund-request.jsp
Use this TurboTax website to check your orders and payments - https://shop.turbotax.intuit.com/commerce/orderstatus/orderstatus.jsp
Go to this TurboTax website for the online editions - https://turbotax.intuit.com/personal-taxes/online/
