How long does Apple Support Legacy OS with Security Updates

[jasonkalman]

So apple supports their legacy OSs with security updates....seems the current one and the prior two. So that would mean once Catalina is released, Mojave and High Sierra will be supported until Catalina is replaced, then High Sierra will drop off. That is good to know since Avid is always way behind in being compatible with the latest OS releases.

https://www.howtogeek.com/350901/whi...urity-updates/

Apple Has No Official Written Policy

Apple doesn’t provide a written statement that guarantees how long it will support each release of macOS with security updates. Apple doesn’t even publicly say when an operating system is “end of life” and is no longer receiving updates. They just stop releasing updates for old versions of macOS with no announcement, and you’re on your own.

This is very unusual if you’re used to dealing with Microsoft Windows. Microsoft publishes their Windows support lifecycle, which spells out precisely (and guarantees) how long each product will receive different types of updates. For example, you can see on that page that for Windows 7 Service Pack 1, mainstream support (new feature releases and minor updates) ended in 2015, but extended support (security updates) goes on until 2020.

Apple does still has a plan, though, even if they don’t describe it publicly. For quite a few years, Apple has consistently updated the last three versions of macOS—in other words, the current release of macOS and the last two releases—with security updates. So, assuming Apple releases a new version of macOS every year, each release of macOS will be supported with security updates for roughly three years. But Apple provides no guarantees, and that’s just an informed guess.

[BScout]

Apple will provide security updates for older macOS versions beyond 3 versions if the problem is severe enough and there's still enough of a user base.

They keep track of the metrics on macOS version conversion (mostly through internet/web usage that gives an identifier of what operating system was in use.) when they release new versions. 3 versions just happens to be when over 90% conversion has usually happened.

[Source is friends who work very high up in product management teams at Apple]

[jasonkalman]

Originally Posted by BScout

Apple will provide security updates for older macOS versions beyond 3 versions if the problem is severe enough and there's still enough of a user base.

They keep track of the metrics on macOS version conversion (mostly through internet/web usage that gives an identifier of what operating system was in use.) when they release new versions. 3 versions just happens to be when over 90% conversion has usually happened.

[Source is friends who work very high up in product management teams at Apple]

Thanks BScout, great to know! It makes me a lot happier knowing this so I can confidently wait to upgrade for years if need be.

[BScout]

Originally Posted by jasonkalman

so I can confidently wait to upgrade for years if need be.

As I mentioned, it's based on metrics. So you are kind of beholden to what the rest of the Mac users do (and by rest, obviously I mean everyone not in audio too.)

[JFreak]

Originally Posted by BScout

3 versions just happens to be when over 90% conversion has usually happened.

That just also happens to be about 3 years