As of this writing, all new Macs require at least Mojave. Usually a Mac requires at least the version of macOS that the model shipped with when it was introduced. Important Notice: these instructions will only work for Mac models that can boot to Mojave. If your organization has blockers for Catalina (incompatible software, etc.) you may want to install Mojave on these Macs.
Apple has started shipping Mac models that used to come with Mojave pre-installed with Catalina.
