---
id: mac-storage-basics.does-time-machine-back-up-external-drives
url: https://storagestudio.us/faq/mac-storage-basics/does-time-machine-back-up-external-drives
category: "Mac storage basics"
subcategory: "Time Machine basics"
question: "Does Time Machine back up my other external drives?"
alt_questions:
  - "time machine include external drive"
  - "back up external drive with time machine"
  - "time machine excludes external drives"
  - "add external disk to time machine backup"
short_answer: "Not by default — external drives are on Time Machine's exclusion list. Remove a drive from the list in Time Machine's Options to include it; it must be connected during backups."
tags: ["time machine", "external drive", "backup"]
related: ["https://storagestudio.us/faq/mac-storage-basics/how-do-i-exclude-folders-from-time-machine", "https://storagestudio.us/faq/mac-storage-basics/how-big-should-a-time-machine-drive-be"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# Does Time Machine back up my other external drives?

Not by default — Time Machine adds external drives to its exclusion list. To include one, open Time Machine's **Options…** in System Settings and remove the drive from the exclusion list. The drive must be connected during backups for its changes to be saved.

Make sure your backup drive is big enough for the extra data.