I normally leave my Mac on and simply close the lid when I'm finished using it. Usually, opening it again only requires Touch ID. However, after using it last night and opening it this morning, I saw a message saying, "Mac requires password to enable Touch ID." I didn't intentionally shut the Mac down, so why did it suddenly ask for my password?
3 Answers
If the Mac actually restarted or installed an update while the lid was closed, it would need the password on the next unlock. After that first password entry, Touch ID should work normally again. A regular sleep cycle usually doesn’t require this by itself, so an automatic update or restart may be worth checking.
This can happen as part of macOS’s normal security rules. Touch ID isn’t allowed indefinitely without a password—for example, a password may be required if it hasn’t been used for about 156 hours, or if biometric authentication hasn’t been used for around four hours. A restart, shutdown, or system update can also trigger the password requirement before Touch ID works again.
The password requirement is also a security feature. After a restart or power-off, the encryption keys needed to access the drive aren’t available until the account password is entered. Touch ID can then be used for later unlocks, but it can’t replace that initial password authentication.

So even if I keep unlocking with Touch ID, it can still eventually require my password? I’m just trying to understand how the timer works.