NIST SP 800-53 Rev. 5 IR-4(3) — Continuity Of Operations

What this control requires

Organization-defined classes of incidents and taking specified actions to ensure continuity of mission and business functions. Actions include system degradation, shutdown, or alternative operations, using tools like incident management systems to maintain operations, aligning with IR-3, CP-2, and CP-4. This control supports the Incident Response Management System capability within the Incident Response family.

In plain English

Organization-defined classes of incidents and taking specified actions to ensure continuity of mission and business functions. In practice, this means you can prove you response 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 critical in the source catalogue. Treat gaps here as production incidents in the risk register, not housekeeping.

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 Incident Response, the assessor will trace your implementation back to the catalogue reference (Control IR-4(3)) 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.

Business Continuity

BC/DR. Define RTO/RPO per service, test backup restoration quarterly, and run a tabletop of full-region failover annually.

Backups. Immutable backups (S3 Object Lock / Azure immutable storage / GCS bucket lock) plus an air-gapped copy for ransomware resilience.

Operational checklist

• Response. Document the trigger, the owner and the cadence.
• Shutdown. Document the trigger, the owner and the cadence.
• System. Document the trigger, the owner and the cadence.
• Control. Document the trigger, the owner and the cadence.
• Alternative. Document the trigger, the owner and the cadence.
• Scope: management, actions, mission, organization, system, functions, incidents, capability.

Evidence to collect

• Ticketing Workflow. ticketing_workflow evidence

Workflow metrics (ServiceNow, Jira) show approvals and remediation. Focus: Continuity Of Operations.

Common pitfalls

• Runbooks that name a role but no person, or list a paging channel that no longer exists.
• DR plans that have never been tested in earnest, or that depend on an MFA token only one person can produce.

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 3.6.5 — Incident Response Plan

Related controls in NIST SP 800-53 Rev. 5

• Control IR-4(5) — Automatic Disabling Of System
• Control SC-47 — Alternate Communications Paths
• Control IR-6(1) — Automated Reporting
• Control IR-4(15) — Public Relations And Reputation Repair
• Control IR-4(4) — Information Correlation
• Control IR-4(11) — Integrated Incident Response Team

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control IR-4(3)

Topics: incident responsechange managementbusiness continuity