As I understand it generally a little less than two years after the final OS upgrade that the machine can accept. Clock is ticking on our 2015 iMac as there is zero chance I'll let my wife continue using it after we no longer get security patches.
Subbed. I'm running a 2012 rMBP and an ancient 2010 17 inch MBP for basic web surfing and am curious if I should retire those machines if we are to use it for something as simple as online purchases even with firewall enabled.
I think Apple gives around 3 years of updates (macOS Catalina stopped getting security updates last year, so 3 years). The same thing for macOS Mojave which stopped getting updates in 2021. So I think you should be good until 2024 ish.
Subbed. I'm running a 2012 rMBP and an ancient 2010 17 inch MBP for basic web surfing and am curious if I should retire those machines if we are to use it for something as simple as online purchases even with firewall enabled.
The 2016 MacBook Pros (including my wife's 15" model) are stuck on Monterey. Ventura doesn't support them. So generally we can expect another year of security updates for Monterey. Possibly two.