NIST SP 800-171 Rev. 3·Requirement 3.6.5·critical·Component: Incident Response

What this control requires

This control requires the development of a comprehensive incident response plan that outlines the organization's approach to incident response, including its structure, reportable incidents, sharing of incident information, and assigned responsibilities. The plan must be distributed to designated personnel, updated regularly, and protected from unauthorized disclosure to ensure effective incident management. This control supports the Incident Response Management capability within the Incident Response (3.6) family.
— NIST SP 800-171 Rev. 3, Requirement 3.6.5

In plain English

This control requires the development of a comprehensive incident response plan that outlines the organization's approach to incident response, including its structure, reportable incidents, sharing of incident information, and assigned responsibilities. In practice, this means you can prove you information management-level controls on a defined cadence.

Why it matters

DoD contractors and their subcontractors must implement all 100 SP 800-171 requirements to keep CUI handling contracts. Gaps are scored against the SPRS scoring methodology; below a 110-point starting score, each unmet requirement deducts points and a below-threshold score can disqualify a bid.

This control is rated critical in the source catalogue. Treat gaps here as production incidents in the risk register, not housekeeping.

What an auditor looks for

A C3PAO conducting a CMMC Level 2 assessment uses NIST SP 800-171A objectives. They expect a System Security Plan (SSP), Plan of Action & Milestones (POA&M) for any gaps, and objective evidence (configurations, ticket records, training records) for every requirement.

Within Incident Response, the assessor will trace your implementation back to the catalogue reference (Requirement 3.6.5) and look for objective evidence on the latest two assessment cycles.

How to implement

Incident Response

Runbook. Maintain a runbook keyed by incident type with named roles (IC, comms, scribe), an out-of-band comms channel, and a 72-hour timeline for external notification.

Tabletop. Run a quarterly tabletop exercise (ransomware, insider, supply-chain) and feed gaps back into the runbook.

Secure Development

Pipeline. Require code review, SAST (Semgrep / Snyk Code), SCA (Dependabot / Renovate), secret-scanning and IaC scanning in the merge pipeline.

Branch protection. Protected branches enforce reviews, signed commits and passing CI before merge; document the protection rules as the control evidence.

Operational checklist

  • Information. Document the trigger, the owner and the cadence.
  • Response. Document the trigger, the owner and the cadence.
  • Incident. Document the trigger, the owner and the cadence.
  • Personnel. Document the trigger, the owner and the cadence.
  • Plan. Document the trigger, the owner and the cadence.
  • Scope: management, response plan, structure, reportable incidents, personnel, development.

Evidence to collect

  • Ticketing Workflow. ticketing_workflow evidence
  • Infra Scan. Continuous infrastructure-posture telemetry — AWS Config, Azure Policy compliance, GCP Organisation Policy, Wiz / Prisma findings.

Workflow metrics (ServiceNow, Jira) show approvals and remediation. Focus: Incident Response Plan.

Common pitfalls

  • Runbooks that name a role but no person, or list a paging channel that no longer exists.
  • CI security checks set to warn-only; the merge button is faster than the security feedback.

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.

Related controls in NIST SP 800-171 Rev. 3

References

Topics: incident responsechange managementsecure development