How To Update Macos High Sierra 10136 To 1015 May 2026

Updating macOS High Sierra

General Steps:

MacBook (Early 2015 or later)
MacBook Air (Mid 2012 or later)
MacBook Pro (Mid 2012 or later)
Mac mini (Late 2012 or later)
iMac (Late 2012 or later)
iMac Pro (2017)
Mac Pro (Late 2013 or later)

Authenticate: Enter your administrator password.

The upgrade begins: Your Mac will restart, show a progress bar, and may restart two or three times. The screen may go black or show an Apple logo with a timer. This is normal.

Install any available firmware or High Sierra updates (Software Update) before upgrading.

4. Verify Your Password and Apple ID

Ensure you know your firmware password (if set – without it, you cannot boot from an installer).
Ensure you know your Apple ID password (the upgrade may ask to re-authenticate).

Stuck on 10.13.6? If your Mac is too old for Catalina, the highest you might be able to go is macOS Mojave (10.14). You can check your specific model via the Apple menu () > About This Mac. how to update macos high sierra 10136 to 1015