# NIST SP 800-53 Rev. 5 AC-4(13) — Decomposition Into Policy-Relevant Subcomponents

- Source: https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-13-decomposition-into-policy-relevant-subcomponents
- 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-4(13)`·high·Component: **Access Control**

## What this control requires

> When transferring information between different security domains, organizations must decompose information into policy-relevant subcomponents for submission to policy enforcement mechanisms. This decomposition helps facilitate policy decisions regarding source, destination, certificates, classification, attachments, and other security- or privacy-related components. This control supports the Governance capability within the Access Control family.
> 
> — NIST SP 800-53 Rev. 5, Control AC-4(13)

### In plain English

When transferring information between different security domains, organizations must decompose information into policy-relevant subcomponents for submission to policy enforcement mechanisms. In practice, this means you can prove you policy 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.

This control is rated **high**. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

## 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-4(13)) and look for objective evidence on the latest two assessment cycles.

## How to implement

#### Policy Management

**Docs.** Keep each policy in version-controlled Markdown alongside the code that implements it; ship a signed PDF snapshot at each annual review and link the SHA into the SoA.

### Operational checklist

-   **Policy.** Document the trigger, the owner and the cadence.
-   **Access.** Document the trigger, the owner and the cadence.
-   **Information.** Document the trigger, the owner and the cadence.
-   **Security.** Document the trigger, the owner and the cadence.
-   **Data.** Document the trigger, the owner and the cadence.
-   **Scope:** management, enforcement, access control, information, privacy, domains, policy-relevant subcomponents, decisions.

## Evidence to collect

-   **Policy Document.** A signed and version-controlled policy / standard / procedure document.

Signed policy or standard documents the safeguard. Focus: Decomposition Into Policy-Relevant Subcomponents.

## Common pitfalls

-   Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced.

## 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.

-   [**NIST SP 800-171 Rev. 3 3.1.9** — System Use Notification](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-1-9-system-use-notification)

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

-   [**Control AC-4(1)** — Object Security And Privacy Attributes](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-1-object-security-and-privacy-attributes)
-   [**Control AC-4(15)** — Detection Of Unsanctioned Information](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-15-detection-of-unsanctioned-information)
-   [**Control AC-4(19)** — Validation Of Metadata](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-19-validation-of-metadata)
-   [**Control AC-4(8)** — Security And Privacy Policy Filters](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-8-security-and-privacy-policy-filters)
-   [**Control AC-4(14)** — Security Or Privacy Policy Filter Constraints](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-14-security-or-privacy-policy-filter-constraints)
-   [**Control AC-4(9)** — Human Reviews](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-9-human-reviews)

## 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-4(13)`

Topics: governance riskdata protectioncertificate managementpolicy managementprivacy management

## 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.