# NIST SP 800-53 Rev. 5 AC-8 — System Use Notification

- Source: https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-8-system-use-notification
- Section: [Compliance](https://support.icompaas.com/compliance) › [NIST SP 800-53 Rev. 5 Controls](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5) › AC — Access Control
- Last updated: 2026-06-05
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

**NIST SP 800-53 Rev. 5**·Control `AC-8`·medium·Component: **Access Control**

## What this control requires

> Display a notification message before granting system access, stating it's a U.S. Government system, usage may be monitored, unauthorized use is prohibited, and use implies consent. Retain until acknowledged. For public systems, include authorized use details. This control supports the User Interface System capability within the Access Control family.
> 
> — NIST SP 800-53 Rev. 5, Control AC-8

### In plain English

Display a notification message before granting system access, stating it's a U.S. In practice, this means you can prove you usage management-level controls on a defined cadence.

## Why it matters

SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed.

## What an auditor looks for

A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan.

Within **Access Control**, the assessor will trace your implementation back to the catalogue reference (Control AC-8) and look for objective evidence on the latest two assessment cycles.

## How to implement

1.  Write a short policy stating intent, scope and named owner.
2.  Encode it as a platform guardrail — SCP, Azure Policy initiative, Organisation Policy, or repository policy.
3.  Wire a monitoring signal that catches drift (CSPM rule, SIEM rule, scheduled query, Workspace alert) and ticket it.
4.  Review on a documented cadence and capture the review in the risk register or compliance tracker.

### Operational checklist

-   **Usage.** Document the trigger, the owner and the cadence.
-   **Access.** Document the trigger, the owner and the cadence.
-   **Review.** Document the trigger, the owner and the cadence.
-   **System Use.** Document the trigger, the owner and the cadence.
-   **Notification.** Document the trigger, the owner and the cadence.
-   **Scope:** management, access control, system, notification, message, identity, review, capability.

## Evidence to collect

-   **Identity Scan.** IAM / IdP exports — Entra ID, Okta, IAM Identity Center, Workspace directory — showing accounts, roles, MFA state and last sign-in.

Identity analytics (Okta, SailPoint, Access Analyzer) demonstrates least-privilege. Focus: System Use Notification.

## How it maps to other frameworks

Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.

-   [**CIS Controls v8 6.7** — Centralize Access Control](https://support.icompaas.com/compliance/cis-controls-v8/6-7-centralize-access-control)
-   [**NIST SP 800-171 Rev. 3 3.1.7** — Least Privilege - Privileged Functions](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-1-7-least-privilege-privileged-functions)
-   [**BSI C5:2020 PS-04** — Physical site access control](https://support.icompaas.com/compliance/bsi-c5-2020/ps-04-physical-site-access-control)
-   [**ISO/IEC 27001:2022 A.8.2** — Privileged access rights](https://support.icompaas.com/compliance/iso-27001-2022/a-8-2-privileged-access-rights)
-   [**SOC 2 (2017 TSC) CC6.1** — Logical Access Controls](https://support.icompaas.com/compliance/soc-2-trust-services-criteria/cc6-1-logical-access-controls)

## Related controls in NIST SP 800-53 Rev. 5

-   [**Control AC-6(6)** — Privileged Access By Non-Organizational Users](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-6-6-privileged-access-by-non-organizational-users)
-   [**Control AC-10** — Concurrent Session Control](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-10-concurrent-session-control)
-   [**Control AC-9** — Previous Logon Notification](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-9-previous-logon-notification)
-   [**Control AC-5** — Separation Of Duties](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-5-separation-of-duties)
-   [**Control AC-11** — Device Lock](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-11-device-lock)
-   [**Control AC-17(10)** — Authenticate Remote Commands](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-17-10-authenticate-remote-commands)

## References

-   [NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5](https://csrc.nist.gov/Projects/risk-management/sp800-53-controls)
-   Catalogue identifier: `Control AC-8`

Topics: identity accessidentity managementaccess reviewprivileged access

## Related compliance guidance

- [NIST SP 800-53 Rev. 5: a practical implementation guide for cloud teams](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5): Start with the full NIST SP 800-53 implementation guide — scope, roadmap, evidence and how the assessment runs.
- [NIST SP 800-171 and CMMC: a practical guide to protecting CUI in the cloud](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3): If your obligation is protecting CUI in your own systems for a federal or defence contract, this derived subset — not the full catalogue — is the requirement.
- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Most commercial SaaS already hold a SOC 2 Type 2, and FedRAMP 20x Class A is designed for providers that have one.
