Apple has confirmed that macOS 28 will no longer support encrypted Mac OS Extended (HFS+) volumes, requiring users to either decrypt or reformat affected drives. The change, documented in a new support article, marks another step in Apple's long-running transition to APFS, which has been the default file system since macOS High Sierra. Starting with macOS 26, Macs will warn users when they connect an encrypted HFS+ volume that won't work on future releases, identifying the problematic drive by name in Disk Utility.

Users can verify whether a volume is both HFS+ and encrypted by opening Disk Utility, selecting Show Only Volumes from the View menu, and checking the format label beneath the volume name. Apple notes that unencrypted HFS+ volumes will continue to function normally.

For migration, Apple outlines two paths: erase and reformat the volume as APFS or APFS (Encrypted), which destroys all data, or decrypt the volume in Finder and optionally convert it to APFS without erasing. The decryption route doesn't apply to encrypted Time Machine backup disks, which require a different workflow.

This move forces anyone still relying on legacy encrypted external drives — particularly creative professionals and long-time Mac users with archival storage — to take action before macOS 28 ships next year. The transition has been gradual, but the hard cutoff eliminates a compatibility layer Apple has maintained for nearly a decade.