Conditional Access: require MFA for all users
Overview
Enforcing MFA via Conditional Access (CA) is the highest ROI identity control for most tenants. Plan exclusions carefully.
Policy pattern
- Create baseline policies: block legacy auth; require MFA for all cloud apps for all users except break-glass.
- Add compliant device or hybrid join policies only where maturity supports—staged rings.
- Use What If tool before enforcement.
Exemptions
Service accounts should use certificates or managed identities—not SMS MFA on a shared phone.
Rollout
Report-only mode → limited enforcement → full; communicate lockout risk for travelers without MFA method backup.
Monitoring
Sign-in logs for failure reason spikes; monthly review of policy gaps when new apps onboard.
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