Microsoft Purview compliance portal: Purview Information Protection | Classifier Simulation Mode (Health Monitoring)
Versions captured by this deployment. Earlier versions and notices may be missing; first observed is not first published.
Rollout
- Ends
- 31 Dec 2026
- Roadmap
- 523201
- Platforms
- Web
Rollout dates are often only in the text. When Microsoft moves them, the change shows under "What changed".
- Microsoft's start date
- 12 Nov 2025
- Last changed by Microsoft
- 14 Jul 2026
- First seen here
- 19 Oct 2026
- Versions seen
- 1
What the notice says
Microsoft's text, with its sections, lists and tables; source markup removedUpdated July 14, 2026: We have updated the timeline. Thank you for your patience.
Introduction
Microsoft Purview is introducing Classifier Simulation Mode, the first phase of the broader Classifier Health Monitoring Platform. This new capability allows admins to test and validate custom classifiers on production data before publishing. Simulation Mode enables admins to optimize classifier logic before deployment, helping in reducing false positives, scanning latency, and noisy matches. Admins will access simulation controls and classifier health insights directly in the Microsoft Purview compliance portal, making it easier to monitor and improve classifier performance in one centralized location.
This message is associated with Roadmap ID 523201.
When this will happen
- Public Preview: Rollout begins mid-October 2026 (previously late June), completes by early November 2026 (previously end of July).
- General Availability (Worldwide): Rollout begins late November 2026 (previously end of July), completes late November 2026 (previously end of August).
How this affects your organization
- Who is affected: Admins managing Microsoft Purview Information Protection and custom sensitive information types (SITs).
- What will happen:
- By default, the feature will be available to all tenants.
- Admins will see a new option to simulate a custom classifier before publishing.
- Simulation is optional — admins can choose to simulate or publish directly.
- Classifiers published without simulation will still be monitored for performance and flagged if unhealthy.
- Classifier health insights will be available in the Microsoft Purview compliance portal, helping admins identify and remediate inefficient classifiers.
- Inefficient classifiers may be automatically disabled to maintain system performance.
What you can do to prepare
- Admins can begin using Simulation Mode once available; no onboarding or training is required.
- Once the feature is available:
- Review classifier health insights in the compliance portal.
- Monitor any SITs flagged as unhealthy and adjust logic as needed.
- Consider simulating classifiers before publishing to reduce risk of false positives or performance issues.
Compliance considerations
| Question | Explanation |
|---|---|
| Does the change alter how existing customer data is processed, stored, or accessed? | Classifiers will be simulated on production data, but not published, allowing analysis without altering data classification outcomes. |
| Does the change introduce or significantly modify AI/ML or agent capabilities that interact with or provide access to customer data? | Introduces classifier health monitoring logic that evaluates classifier performance and flags inefficiencies. |
| Does the change modify how admins can monitor, report on, or demonstrate compliance activities? | Adds new health insights and monitoring capabilities for custom classifiers in the compliance portal. |
| Does the change include an admin control and, can it be controlled through Entra ID group membership? | Simulation and publishing options are available to admins; access can be managed via role-based permissions. |
What changed
Between the versions this installation saw, newest firstThis installation has seen one version of this notice, first on 19 Oct 2026. Later changes will show here.
Linked documentation
Microsoft pages the notice links toThe notice links to no Microsoft Learn or Support page that this installation reads.
Not confirmed here
What this page cannot tell you- Whether your tenant is affected: this is Microsoft's notice, not a check of your settings.
- Versions before 19 Oct 2026: this installation first saw the notice after Microsoft posted it.