Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Dear @Cooper Ruby,
I understand that you are using Microsoft Entra ID Free, with Security Defaults disabled, and are managing MFA through per-user MFA. You would like to know how frequently MFA is requested and whether the authentication frequency can be configured.
With per-user MFA, there is no fixed interval such as every 7, 30, or 90 days at which MFA is guaranteed to appear. When a user is in the Enforced state, MFA is required when Microsoft Entra determines that a new MFA authentication is required during sign-in. Microsoft states that per-user MFA causes users to perform MFA each time they sign in, although session persistence and the “remember MFA on trusted devices” behavior can prevent a new prompt from appearing every time.
Why might MFA not appear again after several days?
If the user previously registered MFA and you temporarily changed the user from Enforced/Enabled to Disabled, then enabled MFA again, the MFA registration itself is not necessarily removed. The user can still have a valid authentication/session state, so simply changing the per-user MFA status does not guarantee that the user will immediately receive a new MFA challenge.
I recommend checking the following:
- Confirm the user’s per-user MFA state
- Entra admin center > Entra ID > Users > Per-user MFA
- Verify the user is Enforced.
- Check whether the user still has registered MFA methods
- Entra admin center > Entra ID > Users > [user] > Authentication methods.
- Confirm that Microsoft Authenticator, phone, or another MFA method is still registered.
- Revoke the user’s existing sessions
From the user’s account, use Revoke sessions.
- This is preferable when the objective is to force the user to authenticate again without deleting their MFA registration. Microsoft documents session revocation as an administrative control for this purpose.
- Check the sign-in logs
- Review Entra ID > Monitoring & health > Sign-in logs.
- Look at the Authentication requirement and authentication details to determine whether MFA was actually required, satisfied by an existing authentication claim/session, or not required for that sign-in. Microsoft also provides authentication-method usage reporting for this purpose.
Can I configure the MFA frequency in Entra ID Free?
This is the important limitation: per-user MFA in Entra ID Free does not provide a configurable “prompt for MFA every X hours/days” setting.
If your requirement is something like:
“Require users to perform MFA again every 24 hours / 7 days / 30 days.”
that is normally controlled using Conditional Access > Sign-in frequency, rather than the per-user MFA state. Microsoft documents Sign-in frequency as the control that determines how long a user can remain signed in before reauthentication is required.
However, Conditional Access requires Microsoft Entra ID P1/P2 (or a license that includes it), so it is not available as a configurable session-frequency control in a basic Entra ID Free-only setup.
Therefore, if you must have a predictable MFA reauthentication interval, I would recommend moving to a license that includes Microsoft Entra ID P1 and using a Conditional Access policy with Sign-in frequency.
For your current Entra ID Free configuration, the practical approach is:
Per-user MFA = Enabled/Enforced > user completes MFA > existing authentication/session state may satisfy subsequent access > revoke sessions when you need to force reauthentication.
Microsoft documentation:
- Enable per-user Microsoft Entra multifactor authentication
- Manage authentication methods for Microsoft Entra MFA
- Conditional Access session controls and Sign-in frequency
I hope this clarifies why MFA is not necessarily prompted again simply because several days have passed, and why per-user MFA itself cannot be configured with a specific MFA frequency.
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