Disabling expired, inactive, or otherwise anomalous accounts supports the concepts of least privilege and least functionality, which reduce the attack surface of the system.
Verify AAA Services is configured to disable accounts when the accounts are no longer associated to a user. If AAA Services is not configured to disable accounts when the accounts are no longer associated to a user, this is a finding.
Configure AAA Services to disable accounts when the accounts are no longer associated to a user.