User level: Level 1 (4 points)My M1 MacBook Air is currently showing that my OS is up to date (20/9/26) with 26.6.2 and wont offer an install of OS 27, on the other hand my M4 Mac has upgraded days ago without any issue, why is this?
Posted on Sep 20, 2026 4:08 AM
User level: Level 10 (123,805 points)Sep 20, 2026 4:16 AM in response to Hodbad
Your M1 MacBook Air is compatible with macOS 27. Apple lists the MacBook Air (M1, 2020) as compatible with macOS 27 Golden Gate, so compatibility is not the reason this model is excluded. (Apple Support)
Apple states that Software Update displays updates that are compatible with the particular Mac. It can therefore report that a Mac is up to date even when a newer major version of macOS exists. (Apple Support)
Because your M1 MacBook Air is running macOS 26.6.2 but is not being offered macOS 27, the next useful step is to determine whether macOS 27 is actually being offered to that Mac through Apple's software-update service.
Open System Settings > General > Software Update and allow it to check for updates. Apple identifies this as the normal method for upgrading to macOS 27. (Apple Support)
If macOS 27 still does not appear, Apple provides a Terminal method for checking which full macOS installers are currently available for your particular Mac. Open Terminal and enter:
softwareupdate --list-full-installers
Apple states that this command displays the macOS versions currently available for the Mac. This is a useful diagnostic because it will establish whether macOS 27 is being offered to the M1 independently of the Software Update preference pane. (Apple Support)
If macOS 27 appears in that list, the full installer can then be downloaded using Apple's Terminal command softwareupdate --fetch-full-installer --full-installer-version 27.0..
If macOS 27 does not appear, that result would provide useful information about why Software Update is not currently offering it.
User level: Level 10 (123,805 points)Sep 20, 2026 12:06 PM in response to Hodbad
OP wrote softwareupdate --fetch-full-installer --full-installer-version 27.0..
Try this command softwareupdate --fetch-full-installer --full-installer-version 27.0 NOTE, there are no trailing period period
User level: Level 6 (17,937 points)Sep 20, 2026 4:17 AM in response to Hodbad
How full is your drive? OS27 is a large file. You need enough extra space for the install to take place.
User level: Level 1 (4 points)Sep 20, 2026 4:29 AM in response to tbirdvet
I have over 160 gigs available
User level: Level 1 (4 points)Sep 20, 2026 9:45 AM in response to Owl-53
Unfortunately this was not successful
User level: Level 1 (4 points)Sep 20, 2026 11:08 PM in response to Owl-53
Bingo, thank you Owl-53
User level: Level 10 (123,805 points)Sep 21, 2026 12:53 AM in response to Hodbad
You are welcome
Upon more careful review of my early posting, it was I who provided a malformed Terminal command with the trailing period period
Thank you for the feedback
Originally posted at discussions.apple.com/thread/256361096