Do manually added contacts stay in a smart group forever?
It is answered here: https://docs.civicrm.org/user/en/latest/organising-your-data/smart-groups/#adding-and-removing-smart-group-members-manually
&quot;You can override the criteria by manually adding or removing contacts from the group&quot;. So, unless the group is deleted or you remove them, my assumption is yes they will stay 'forever'.