# NIST SP 800-53 Rev. 5 SA-23 — Specialization

- Source: https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-23-specialization
- 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) › SA — System and Services Acquisition
- Last updated: 2026-06-05
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

**NIST SP 800-53 Rev. 5**·Control `SA-23`·high·Component: **System and Services Acquisition**

## What this control requires

> Employ design, modification, augmentation, or reconfiguration on organization-defined systems or components supporting mission-essential services to increase trustworthiness. Enhancements may include supplemental authentication or non-repudiation functions. This control supports the Specialized Trust Enhancement Framework capability within the System and Services Acquisition family.
> 
> — NIST SP 800-53 Rev. 5, Control SA-23

### In plain English

Employ design, modification, augmentation, or reconfiguration on organization-defined systems or components supporting mission-essential services to increase trustworthiness. In practice, this means you can prove you access 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 **System and Services Acquisition**, the assessor will trace your implementation back to the catalogue reference (Control SA-23) 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

-   **Access.** Document the trigger, the owner and the cadence.
-   **Review.** Document the trigger, the owner and the cadence.
-   **Authentication.** Document the trigger, the owner and the cadence.
-   **Non-Repudiation.** Document the trigger, the owner and the cadence.
-   **System.** Document the trigger, the owner and the cadence.
-   **Scope:** management, mission, authentication, organization, system, functions, identity, review.

## 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: Specialization.

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

-   [**Control SA-8(9)** — Trusted Components](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-8-9-trusted-components)
-   [**Control SA-9(6)** — Organization-Controlled Cryptographic Keys](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-9-6-organization-controlled-cryptographic-keys)
-   [**Control SA-21** — Developer Screening](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-21-developer-screening)
-   [**Control SA-19(3)** — Component Disposal](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-19-3-component-disposal)
-   [**Control SA-8(6)** — Minimized Sharing](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-8-6-minimized-sharing)
-   [**Control SC-11** — Trusted Path](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-11-trusted-path)

## 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 SA-23`

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.