Apple has issued a clear warning to users still relying on older encrypted storage: starting with macOS 28 (expected in 2027), the company will drop support for encrypted volumes formatted with Mac OS Extended, also known as HFS+.
In a new support document published this week, Apple states that in macOS 28 and later, the Mac OS Extended file system format will be supported only for unencrypted volumes. Encrypted HFS+ drives — common on older external hard drives and backups created with FileVault-style encryption via CoreStorage — will no longer be readable without prior action.
Why This Change Matters
Apple has been gradually shifting away from the aging Mac OS Extended format since introducing the more modern and efficient APFS (Apple File System) in 2017. APFS offers native encryption, better performance, snapshot capabilities, and improved data integrity. While unencrypted HFS+ volumes will continue to work in macOS 28 and beyond, encrypted legacy volumes are now being retired to simplify the codebase and encourage migration to modern standards.
Users may begin seeing warnings as early as macOS 26, which can alert them to incompatible encrypted Mac OS Extended drives.
How to Check If Your Drives Are Affected
- Open Disk Utility (in Applications > Utilities).
- From the View menu, choose Show Only Volumes.
- Select the volume in the sidebar.
- Look at the details on the right. If it shows both “Mac OS Extended” and “Encrypted” (e.g., “CoreStorage Logical Volume • Mac OS Extended (Case-sensitive, Journaled, Encrypted)”), the drive will not be compatible with macOS 28.
Note: This change does not affect APFS-formatted drives (encrypted or not) or unencrypted HFS+ volumes.What You Should Do NowApple strongly recommends backing up your data first. Then choose one of these options before upgrading to macOS 28:
• Decrypt the volume (preserves data without erasure): Connect the drive, unlock it with the password, Control-click the drive icon, and select Decrypt. This process can take a long time for large drives. After decryption, you can optionally convert it to APFS.
• Reformat the volume (recommended for long-term use): Erase and reformat using APFS or APFS (Encrypted). This will delete all existing data, so ensure you have a complete backup.
For detailed step-by-step instructions, refer to Apple’s official support document: About support for encrypted Mac OS Extended disks in macOS 28 or later.
MacDailyNews Take: This move aligns with Apple’s long-term strategy to retire legacy technologies. Users with older encrypted external drives or Time Machine backups should act soon to avoid data access issues next year. If you’re unsure about your storage setup, checking with Disk Utility now is a quick and safe first step.
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