Mac Hardware has a minimum and maximum version of macOS that can be installed. What is the minimum and maximum macOS Version my Mac can run? Do you need to downgrade or upgrade macOS on your Mac? This page will show you the oldest and newest version of macOS that you can install on your Mac.Ĭan I upgrade or downgrade macOS? How many times has this question come up over the years? Probably hundreds if not thousands of times.