From Anton Willoughby: https://www.linkedin.com/pulse/dynamically-exclude-new-hires-from-conditional-access-willoughby-qfadc%3FtrackingId=VVFS7AtiRPWYQjwM5PU3mQ%253D%253D/?trackingId=VVFS7AtiRPWYQjwM5PU3mQ%3D%3D Leverage Entra ID Dynamic Groups and use the "Employee hire data" property in the query to add users to the group based on their start date. Then, have this group in the Conditional Access Exclusions