I’m running macOS 18 and since I depend on dark mode, macOS 26 seems like a step backwards for my eye sensitivity.
So I’d like to stay on 18 for as long as it receives security updates and consider upgrade options some time later. Do the ISOs tend to remain available? Because my understanding is that when it comes to iOS, if you miss the last chance to upgrade, you’re stuck with whatever you have.


The only time you’re locked to an OS release is if your hardware can no longer support it. In the case of Apple hardware, that tends to be five or six or even seven years after that particular hardware was last sold. And even then you may still get the odd security update for a few years after that.
My 2015 MacBook Pro is currently running Mojave (by choice). I can upgrade to a newer macOS whenever I want, but because this hardware is a decade old I can only upgrade up to Monterey. I cannot upgrade to Tahoe, I would need a newer computer.
Thanks. I’m on an M1 Mac so I’ll hold off. Maybe macOS 27 will have more refinements or options for people like me who rely on accessibility features for light sensitivity.