NIST SP 800-53 Rev. 5 PT-3 — Personally Identifiable Information Processing Purposes

What this control requires

Identify, document, and restrict the processing of personally identifiable information (PII) to only that which is compatible with defined purposes. Ensure that the processing aligns with privacy policies and is communicated in public notices, with changes in processing monitored and aligned with organizational requirements.

In plain English

Identify, document, and restrict the processing of personally identifiable information (PII) to only that which is compatible with defined purposes. 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 Purpose Identification and Processing Controls, the assessor will trace your implementation back to the catalogue reference (Control PT-3) 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.
• Restrict. Document the trigger, the owner and the cadence.
• Information. Document the trigger, the owner and the cadence.
• Changes. Document the trigger, the owner and the cadence.
• Identify. Document the trigger, the owner and the cadence.
• Scope: management, information, privacy, only, controls, personally identifiable information, identification, purpose.

Evidence to collect

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

Signed policy or standard documents the safeguard. Focus: Personally Identifiable Information Processing Purposes.

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.

• HIPAA (45 CFR Part 164) 164.502(j)(2) — Disclosures by workforce members who are victims of a crime
• ISO/IEC 27001:2022 A.8.26 — Application security requirements
• SOC 2 (2017 TSC) P3.2 — Consent Management for Personal Information Collection
• GDPR Article 11 — Processing which does not require identification

Related controls in NIST SP 800-53 Rev. 5

• Control PT-7 — Specific Categories Of Personally Identifiable Information
• Control PT-2(2) — Automation
• Control PT-3(1) — Data Tagging
• Control PT-3(2) — Automation
• Control PT-2(1) — Data Tagging
• Control SI-19 — De-Identification

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control PT-3

Topics: governance riskprivacy managementpolicy management