What new operating system will work on my iMac, 10.12.6 with Sierra

The model year of an iMac is available at Apple menu > About This Mac.

A late 2009 through mid 2011 iMac can be upgraded to High Sierra 10.13.6 but no later version. See: How to download macOS - Apple Support

A late 2012 through late 2013 iMac can be upgraded to Catalina 10.15.7 but no later. See: How to download macOS - Apple Support

A mid 2014 and late 2014 iMac can be upgraded to the latest version of Big Sur macOS 11 but no later. See: How to download macOS - Apple Support

A late 2015 iMac can be upgraded to the latest version of Monterey macOS 12. See:How to download macOS - Apple Support

A 2017 or later iMac can be upgraded to the current version of Ventura macOS 13. See: How to upgrade to macOS Ventura - Apple Support

nd1214 wrote:

Hello FoxFifth! Excuse my ignorance, but does this also apply to a macbook pro? I have an early 2013 15" in need of upgrading. Thanks for your help!

Anearly 2013 MacBook Pro can be upgraded to Catalina 10.15.7 but no later. See: How to download macOS - Apple Support

Be aware that if you upgrade to Catalina 10.15 or later you will also need to update any non-Apple 32-bit apps. See: https://www.macworld.com/article/232735/how-to-check-if-mac-software-is-32-or-64-bit.html

PPcheerleader wrote:

I upgraded my 2016 iMac with Sierra to Monterey 12.6.5 with the help of the Apple Support Community. My email was recently hacked as despite thinking Best Buy Webroot was working, only the icon was there. Perhaps it quit working when I upgraded?? Is there a free security system I could install or could someone suggest the one they think is best? Thank you for your help.

I wouldn't install any myself and note that an email password can be hacked without gaining access to your Apple device(s).

For me personally:

macOS - Security - Apple

Apple Platform Security - Apple Support

Security features for MacBook Pro - Apple Support

Protecting against malware in macOS - Apple Support

But is someone somehow forced me, the only one I would personally consider is https://support.malwarebytes.com/hc/en-us/categories/360002468253-Malwarebytes-for-Mac

Let us know if there is anything else we can help with. Lots of people here to do that.

Hello FoxFifth! Excuse my ignorance, but does this also apply to a macbook pro? I have an early 2013 15" in need of upgrading. Thanks for your help!

Thank you!