Apple is updating its support documentation to state that macOS 28 will no longer support encrypted Mac OS Extended (HFS+) volumes. The change affects storage devices formatted with HFS+ encryption, which include some older encrypted external hard drives and other legacy encrypted volumes. According to Apple, only unencrypted HFS+ volumes remain supported in macOS 28 and later. Users with encrypted HFS+ drives will need to take action before upgrading—either decrypt the drive or reformat it to APFS (including options to use APFS encryption).

Apple does not cite a specific reason for dropping encrypted HFS+ support. Multiple outlets note that APFS has supported encryption natively since it became the default file system in 2017, and the shift appears consistent with Apple’s longer transition away from HFS+. Apple also says that starting with macOS 26, some Macs may display notifications when an encrypted HFS+ volume is detected that will not carry over to macOS 28, identifying the volume by name. AppleInsider and others add that unencrypted HFS+ volumes continue to work, while encrypted Time Machine backup disks are not covered by the deprecation notice.