03.06.03: Incident Response Testing

To meet the 03.06.03: incident response testing requirement, you must regularly test your incident response capability in the environment that handles CUI, document results, and track corrective actions to closure. Treat testing as an operational control: planned scenarios, defined success criteria, recorded evidence, and improvements that feed back into your incident response plan and training. ¹

Key takeaways:

• Run planned incident response tests (tabletop and, where feasible, technical exercises) against your CUI-relevant systems. ¹
• Keep assessor-ready evidence: test plans, attendance, artifacts, after-action reports, and remediation tracking. ¹
• Close the loop: update playbooks, roles, escalation, and tooling based on test findings, then prove the updates happened. ¹

“Incident response testing” is where most programs fail in audits, not because teams never respond to incidents, but because they can’t prove they rehearsed, measured performance, and improved the process for the systems that handle CUI. Requirement 03.06.03: Incident Response Testing in NIST SP 800-171 Rev. 3 pushes you past a written incident response plan and into repeatable operational readiness: you test, you learn, you fix, you retest.

For a CCO, compliance officer, or GRC lead, operationalizing this requirement means building a testing cadence that your security team can actually run, and that produces evidence an assessor can follow end-to-end. Your goal is simple: demonstrate that incident response is not ad hoc. You can show planned exercises, realistic scenarios tied to your CUI environment, defined roles, and tracked corrective actions that materially improve response outcomes. ¹

This page gives you requirement-level implementation guidance: who owns what, what to run, what to save, what auditors ask for, and how to stand up an execution program quickly without turning it into a one-time “annual tabletop” that doesn’t change anything.

Regulatory text

Excerpt / reference: “NIST SP 800-171 Rev. 3 requirement 03.06.03 (Incident Response Testing).” ¹

What the operator must do: You need an incident response testing practice that validates your incident response plan and operational readiness for the systems and workflows that process, store, or transmit CUI. Testing must be deliberate (planned), repeatable, and documented, with evidence that you addressed identified gaps through corrective actions and updates to procedures and training. ¹

Plain-English interpretation (what this requirement is really asking)

You must practice incident response the same way you practice disaster recovery: run exercises, confirm people know their roles, confirm tooling and access work, and prove you improved the process after each test. A “test” can be a tabletop discussion, a call-tree drill, or a more technical simulation, but it has to be credible for your environment and produce records that show what happened and what changed afterward. ¹

The control fails in audits for two common reasons:

1. No evidence of testing (or only informal chats with no artifacts).
2. No evidence of improvement (tests happen, findings exist, but nobody fixes root causes or updates the plan).

Who it applies to (entity and operational context)

This applies to nonfederal organizations handling CUI and federal contractors that must implement NIST SP 800-171 controls in the environment where CUI lives. ¹

Operationally, scope this to:

• The CUI boundary: enclaves, networks, endpoints, identity systems, and cloud services in the authorized environment.
• Incident response participants: security operations, IT, cloud admins, legal/compliance, HR (for insider scenarios), physical security (if relevant), and executive decision makers for severity thresholds.
• Third parties: MSSPs, IR retainers, cloud providers, and key SaaS tools involved in detection, containment, forensics, or communications. Treat them as in-scope if they have roles during an incident in your CUI environment.

What you actually need to do (step-by-step)

Step 1: Define your testing scope and objectives

Create a one-page Incident Response Testing Charter that states:

• Which systems and locations are in scope (tie to your CUI system inventory / boundary).
• Which roles must participate (RACI for incident commander, comms lead, forensics, IT ops, compliance).
• What you are validating (examples: escalation, evidence collection, containment steps, access to logs, third-party engagement).
• What success looks like (objective pass/fail or maturity criteria).

This document is small but powerful in audits because it proves intent and scope control.

Step 2: Build a realistic scenario library mapped to your environment

Maintain 6–10 scenarios (you can start smaller) that cover credible threats to the CUI environment, such as:

• Compromised privileged account in identity provider.
• Suspected exfiltration from CUI file store.
• Ransomware on a CUI workstation segment.
• Third-party compromise affecting your CUI workflow.
• Misconfiguration exposing CUI in cloud storage.
• Insider copying CUI to unauthorized media.

For each scenario, write:

• Trigger and initial signals (alerts, user reports, audit log anomalies).
• Key decision points (who declares an incident, when to isolate systems, when to engage third parties).
• Required artifacts (logs, tickets, evidence chain-of-custody notes).
• Communications requirements (internal escalation path, customer/government contracting notifications if applicable to your contract terms).

Step 3: Choose test types and run them as a program

Use a mix, because auditors look for operational breadth:

• Tabletop exercises: validate decision making, roles, communications, and playbook clarity.
• Operational drills: validate that call trees work, access is pre-provisioned, and tickets get created correctly.
• Technical simulations (where feasible): validate detection-to-containment actions, log access, and forensic readiness.

Your testing method should match your environment’s risk and complexity. If your CUI environment is cloud-heavy, include scenarios that force access to cloud logs and IAM changes.

Step 4: Execute tests with facilitator notes and objective scoring

For each test:

• Assign a facilitator (often GRC or security) and a scribe.
• Use a structured runbook: timeline, injects, decisions, and required actions.
• Record attendance and roles.
• Capture timestamps for key milestones (detection acknowledged, incident declared, containment initiated). Avoid numeric performance claims in reports unless you measured them from logs or tickets.

Deliverable: a completed exercise packet with notes, decisions made, and observed gaps.

Step 5: Produce an After-Action Report (AAR) with corrective actions

Every test must end with:

• What happened (brief narrative).
• What worked (specific, repeatable actions).
• What failed (process gaps, unclear ownership, tooling access problems).
• Corrective actions with owners and due dates (your internal due dates, not a regulatory mandate).

Then track the actions to closure in your normal governance tooling (ticketing system, GRC platform, or risk register).

Step 6: Update the incident response plan and related procedures

This is the closure loop auditors hunt for. Update:

• Incident response plan (roles, escalation criteria, severity definitions).
• Playbooks/runbooks (steps for containment, evidence collection, third-party engagement).
• Contact lists and call trees.
• Logging and access prerequisites (who can access what, how quickly).
• Training content for responders and executives.

Keep redlines or version history so you can prove the plan changed because of testing.

Step 7: Collect recurring evidence, centrally, in an assessor-ready format

Create a standard folder structure per test (or a control record in Daydream) that links:

• Exercise plan
• Scenario
• Attendance
• Notes/artifacts
• AAR
• Corrective action tickets
• Proof of closure
• Updated plan version

A tool like Daydream helps by mapping the 03.06.03: incident response testing requirement directly to your policy/control statement and to recurring evidence requests, so you do not rebuild the evidence trail during an assessment.

Required evidence and artifacts to retain (audit-ready checklist)

Retain these artifacts for each test cycle:

• IR Testing Policy/Standard (states cadence and test types, scope, participants).
• IR Testing Calendar / Plan (scheduled exercises and objectives).
• Scenario scripts and injects (version-controlled).
• Attendance records (names, roles, orgs, including third parties if participating).
• Facilitator notes and outputs (decisions made, actions taken).
• After-Action Report (AAR) with findings and corrective actions.
• Corrective action tracking (tickets with owners, status, closure evidence).
• Updated incident response plan/playbooks (version history and approval).
• Evidence of responder access readiness (examples: screenshots or access request records showing responders can reach logging, EDR, SIEM, cloud audit logs, and case management systems as required for your environment).

Common exam/audit questions and hangups

Expect questions like:

• “Show me the last incident response test for the CUI boundary and the artifacts produced.” ¹
• “How do you decide scenarios, and how do they map to your system architecture?” ¹
• “Where are corrective actions tracked, and how do you prove closure?” ¹
• “Who participated, and do they match the roles defined in the IR plan?” ¹
• “What changed in your incident response plan as a result of testing?” ¹

Hangups that create delays:

• Evidence scattered across chat, email, and whiteboards.
• Tabletop-only programs with no operational drills.
• “Lessons learned” documented but not assigned to owners with closure evidence.

Frequent implementation mistakes and how to avoid them

Mistake	Why it fails	Fix
Running one generic tabletop unrelated to the CUI environment	Assessors look for relevance to the in-scope system boundary	Build scenarios tied to your CUI architecture and data flows
No written success criteria	You can’t show the test validated anything	Define specific objectives per exercise (access, escalation, containment, evidence handling)
No corrective action tracking	Testing looks ceremonial	Open tickets, assign owners, record closure evidence
Tests exclude key stakeholders	Real incidents require cross-functional decisions	Include IT, security, compliance/legal, and third parties with IR roles
No version history of plan updates	You can’t prove improvements	Keep version-controlled IR plan and playbooks, link changes to AAR items

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this requirement, so you should treat “enforcement context” here as assessment and contractual risk rather than citing specific actions.

Practically, weak incident response testing increases:

• Containment and recovery risk because responders may lack access, authority, or practiced decision paths.
• Assessment failure risk because this control is evidence-driven. Auditors usually accept “we had no incidents” only if you can show you still tested readiness. ¹
• Third-party dependency risk because many CUI environments rely on MSSPs and cloud providers. If you have never tested engagement and evidence exchange, response can stall.

Practical 30/60/90-day execution plan

First 30 days (stand up the minimum viable program)

• Confirm CUI boundary and identify IR participants for that scope.
• Draft IR Testing Charter and a simple testing standard (what you test, who runs it, evidence you keep).
• Build your first two scenarios tied to your environment (one credential compromise, one data exposure/exfiltration).
• Create evidence templates: exercise plan, sign-in sheet, AAR, corrective action log.
• Run one tabletop and publish the AAR with assigned corrective actions.

Days 31–60 (make it operational and measurable)

• Convert corrective actions into tickets and close the highest-impact gaps (access to logs, missing runbooks, unclear escalation).
• Run an operational drill (call tree + opening an incident ticket + pulling required logs).
• Update IR plan/playbooks based on the AAR and record approvals.
• Validate third-party participation paths (MSSP escalation, IR retainer contact, cloud support procedures) and document them.

Days 61–90 (prove repeatability and close the loop)

• Run a second exercise type (tabletop if first was drill, or drill if first was tabletop), using a different scenario.
• Demonstrate closure: show completed corrective actions from the first test and the resulting plan updates.
• Establish recurring governance: quarterly planning meeting, scenario refresh, and evidence review workflow.
• If you use Daydream, finalize the control mapping and set recurring evidence requests so testing artifacts are collected continuously rather than at audit time.

Frequently Asked Questions

Do we have to run a “red team” or penetration-style exercise to satisfy 03.06.03?

The requirement is incident response testing, so tabletops and operational drills can satisfy it if they are realistic, documented, and lead to improvements. Add technical simulations where feasible for your environment and risk profile. ¹

What if we haven’t had any incidents this year?

A lack of real incidents does not remove the need to test readiness. Use planned exercises to prove your team, tools, and third-party engagement paths work for the CUI boundary. ¹

How do we scope testing when CUI exists in multiple tools and locations?

Anchor scope to your defined CUI boundary and the data flows that touch CUI. Then select scenarios that force actions across those systems (identity, endpoint, cloud logs, ticketing, storage). ¹

Can a third party (MSSP or IR retainer) run the test for us?

Yes, but you still own the control and must retain evidence, decisions, and corrective actions. Make sure roles, communications, and handoffs are tested, not just the third party’s internal process. ¹

What evidence is most persuasive to auditors for this requirement?

A complete chain: test plan and scenario, attendance, facilitator notes, an AAR with assigned corrective actions, tickets showing closure, and an updated IR plan or playbook with version history tied to the findings. ¹

How do we keep this from becoming a “paper exercise”?

Add at least one drill that requires real access and real artifacts, such as pulling audit logs, isolating a test endpoint, or executing a containment change in a controlled way. Then track fixes like any other operational work item. ¹

Footnotes

1. NIST SP 800-171 Rev. 3