Apple has confirmed that macOS 28 will no longer support encrypted volumes using the legacy Mac OS Extended (HFS+) file system, forcing users to decrypt or reformat affected drives to maintain compatibility.
What’s Changing and Why
Starting with macOS 28, Apple will only support non-encrypted Mac OS Extended volumes. Encrypted HFS+ external drives, Time Machine backups, and other legacy volumes will be incompatible unless the user takes proactive steps. Apple has not publicly stated a rationale, but the move aligns with its long-term migration to APFS, which became the default file system in macOS High Sierra and offers native encryption.
APFS provides integrated, more efficient encryption than the CoreStorage-based encryption used with HFS+. This deprecation effectively removes a legacy encryption pathway that Apple no longer wishes to maintain.
How to Find the Drives at Risk Before It Is Too Late
Apple will begin issuing warnings in macOS 26, flagging encrypted HFS+ volumes that will fail under macOS 28. Users can manually check via Disk Utility: select a volume and look for both “Mac OS Extended” and “Encrypted” in the information pane. A typical indicator is “CoreStorage Logical Volume • Mac OS Extended (Case-sensitive, Journaled, Encrypted).”
Unencrypted HFS+ volumes will continue to work normally under macOS 28 and later.
Choosing Where to Move Your Data Before the Deadline
Apple offers two primary options. The first is to reformat the volume to APFS or APFS (Encrypted), which permanently erases all data. A full backup is mandatory before proceeding. The second is to decrypt the volume, preserving the data, then optionally convert to APFS without erasing it via Disk Utility’s “Convert to APFS” command. Note that decryption does not apply to encrypted Time Machine backup disks.
After decryption, users can re-encrypt the APFS volume using Finder’s context menu. Apple recommends using Terminal’s `diskutil cs list` command to monitor decryption progress on large drives.
Why Organizations Face a Ticking Clock on Legacy Storage
For IT administrators and professionals managing fleets of Macs or legacy storage workflows, this deprecation signals a firm deadline for migration. Encrypted HFS+ volumes should be identified and transitioned well before macOS 28’s release. While Apple is providing a two-year runway starting with macOS 26 warnings, the window for action is finite. Organizations still reliant on encrypted HFS+ should treat this as a compliance and data continuity requirement, not a convenience suggestion.
— Originally reported by 9to5Mac. Adapted and republished with editorial context for AppleThreat.
