RS.MA-01: The incident response plan is executed in coordination with relevant third parties once an incident is declared

The rs.ma-01: the incident response plan is executed in coordination with relevant third parties once an incident is declared requirement is about execution discipline under pressure. Most programs have an incident response plan on paper, but coordination breaks down when external parties need to act quickly: a cloud provider must preserve logs, an MSP must isolate systems, outside counsel must manage privilege, a forensics firm must image endpoints, a payment processor must validate fraud controls, or a critical supplier must confirm compromise scope.

RS.MA-01 pushes you to treat third-party involvement as part of incident response operations, not procurement admin. For a Compliance Officer, CCO, or GRC lead, the fastest path to operationalizing this requirement is to (1) define what “incident declared” means in your environment, (2) pre-assign third parties to common incident types, (3) ensure contracts and access enable rapid engagement, and (4) retain evidence that coordination occurred during the incident timeline.

The practical goal: during an incident, nobody debates who to call, what they’re allowed to do, or how actions get tracked. You can prove it later with a clean, time-ordered record.

Regulatory text

Excerpt (RS.MA-01): “The incident response plan is executed in coordination with relevant third parties once an incident is declared.” (NIST CSWP 29; NIST CSF 1.1 to 2.0 Core Transition Changes)

Operator interpretation: Once your organization formally declares an incident under your incident classification criteria, you must execute the response plan in a way that actively involves the external parties who have a role in containment, eradication, recovery, communications, legal/regulatory response, or supporting evidence preservation. The requirement is not satisfied by having third parties listed in a plan; it is satisfied by demonstrable coordination during real incidents and exercises. (NIST CSWP 29)

Plain-English requirement interpretation

You need three things working together:

1. A declaration trigger that flips you into “incident mode.” If declaration is vague or informal, you will not be able to prove the “once an incident is declared” timing.
2. A scenario-based map of which third parties are “relevant.” Relevance depends on the systems and services affected, not who is easiest to reach.
3. An execution method that produces a coordination record. During the incident, you must capture decisions, tasks, notifications, handoffs, and outcomes across internal teams and third parties.

If you only notify third parties after you have already contained the event, auditors will treat that as ad hoc support, not coordinated execution.

Who it applies to (entity and operational context)

Entity scope: Any organization operating a cybersecurity program that uses third parties to deliver, operate, secure, or advise on technology and business services. (NIST CSWP 29)

Operational contexts where RS.MA-01 usually bites:

• Cloud and SaaS dependency: You need provider engagement for logs, isolation actions, and service-side root cause detail.
• Managed service providers (MSP/MSSP): They may hold the tooling keys for EDR, SIEM, firewall changes, or identity controls.
• Payment, payroll, benefits, and customer data processors: Incidents can require joint investigation and coordinated customer/regulator communications.
• External counsel and forensics: Privilege strategy, evidence handling, and breach response often require pre-arranged engagement.
• Critical suppliers and partners: A compromise may be upstream or lateral, requiring coordinated scoping and containment.

If your third-party ecosystem can affect availability, integrity, or confidentiality of your services, RS.MA-01 applies in practice.

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

1) Define “incident declared” in a way you can execute

• Set declaration authority: name the role(s) that can declare (for example, Incident Commander, CISO delegate, on-call lead).
• Define declaration criteria: tie to severity levels, business impact, legal/regulatory trigger points, or confirmed compromise.
• Embed the declaration in tooling: make “incident declared” a status change in your IR ticket/case system so time stamps are automatic.

Evidence outcome: a record that shows the declaration moment and who approved it.

2) Build a “relevant third parties” register tied to incident scenarios

Create a table that answers: If this incident type happens, who must coordinate, what do they do, and how fast must they respond?

Minimum columns that work in audits:

• Incident type (ransomware, BEC, SaaS compromise, cloud misconfig, DDoS, insider, third-party breach notification)
• Impacted service/system
• Third party name and role (provider, processor, counsel, forensics, PR, call center, MSP/MSSP)
• Primary and backup contacts (named individuals or monitored distribution lists)
• Engagement mechanism (hotline, portal, contract vehicle, retainer, support plan)
• Required actions (preserve logs, isolate tenant, disable accounts, provide IOCs, image endpoints)
• Target response expectation (your internal expectation; keep it consistent with contracts)

Make it executable: store the register where responders will look first (IR runbook, case template, on-call wiki).

3) Align contracts, support terms, and retainers to incident needs

Coordination fails when third parties cannot act without procurement, SOW changes, or legal review. Close the common gaps:

• Right to request assistance during incidents: include contractual language that defines incident support obligations for critical providers.
• Log retention and evidence support: confirm you can request relevant logs and preservation steps.
• Breach notification and cooperation: require timely notification and cooperation in investigations and customer/regulator response.
• Subprocessor visibility: for key processors, ensure you can identify downstream parties involved in the affected service chain.
• Retainers: for external forensics and breach counsel, have engagement pre-approved so you can activate immediately.

Compliance angle: you are reducing the risk that response actions are delayed for administrative reasons, which undermines coordinated execution.

4) Put third-party coordination into the incident command structure

Your plan should explicitly assign coordination tasks:

• Third-Party Liaison (role): single-thread coordination to avoid duplicate requests and conflicting directions.
• Legal liaison: if counsel is involved, define how privilege is handled and what communications go through legal.
• Comms lead: manages coordinated external messaging with relevant third parties (providers, partners) and internal stakeholders.

Use a RACI-style model inside the incident plan: who is responsible for requesting support, approving containment actions, and confirming completion.

5) Create “notification and handoff” playbooks and templates

During an incident, speed and accuracy matter. Pre-write:

• Third-party incident notification template (what happened, suspected scope, time window, requested actions, deadlines, secure reply channel)
• Evidence preservation request template (log sources, retention hold, chain of custody expectations)
• Status update cadence (who updates whom, via what channel)

Practical tip: Keep templates short. Long forms lead to incomplete notices.

6) Exercise the coordination, not just the internal steps

Run tabletop exercises that require third-party participation or realistic simulation:

• Invite critical providers to join a tabletop segment, or
• Simulate the interaction with scripted “provider responses” and document decisions, escalation, and timing.

Track issues as backlog items: missing contacts, unclear roles, support plan limitations, insecure comms paths.

7) During a real incident: run coordination through your case record

To make RS.MA-01 defensible, your incident record should show:

• When the incident was declared
• When each relevant third party was engaged (time stamps)
• What was requested and what was delivered
• Key decisions that depended on third-party input (containment choices, recovery sequencing)
• Escalations and fallbacks (backup contacts, alternate providers)

A common operational pattern is to run all third-party tasks as tickets linked to the master incident.

Required evidence and artifacts to retain

Auditors usually want proof of both design (you planned for coordination) and operation (you did it).

Design artifacts

• Incident Response Plan with third-party coordination roles and triggers (NIST CSWP 29)
• Third-party incident coordination register (scenario-to-third-party mapping)
• Contact rosters with primaries/backups and secure communication methods
• Contract excerpts or addenda showing incident cooperation obligations (where applicable)
• Retainer letters / engagement playbooks for outside counsel and forensics (if used)

Operational artifacts

• Incident declaration record (ticket status change, approval note)
• Communication logs (email headers, portal submissions, chat exports) with third parties
• Third-party provided deliverables (logs, incident reports, RCA summaries, containment confirmations)
• Timeline of events (internal + third-party actions)
• After-action report with third-party performance notes and remediation tasks

Common exam/audit questions and hangups

Expect questions like:

• “Show me how you define ‘incident declared’ and where that’s recorded.”
• “Which third parties are considered relevant for a SaaS identity compromise? Show the mapping.”
• “Provide an incident where a third party participated. Where is the evidence?”
• “How do you ensure third parties can act quickly without a new SOW?”
• “Who owns third-party communications during an incident, and how do you prevent conflicting requests?”

Hangups that trigger findings:

• Contacts are stale or owned by one person’s inbox.
• The plan lists third parties, but no incidents or exercises show engagement.
• Third-party obligations exist in theory, but contracts do not support urgent cooperation.

Frequent implementation mistakes and how to avoid them

Mistake	Why it fails RS.MA-01	Fix
“Relevant third parties” is a generic list	Not tied to incident type or assets; responders don’t know who to call	Build scenario-based mapping and embed it in runbooks
Coordination happens over informal channels	No audit trail; hard to prove timing and decisions	Route requests through the incident ticket and approved comms channels
Procurement gates block activation	Delays engagement after declaration	Pre-negotiate incident support clauses and retainers
Multiple internal teams contact the same provider	Conflicting instructions; provider fatigue	Assign a Third-Party Liaison role and enforce single-threading
Exercises exclude third parties	You never validate real coordination	Include third parties or simulate interaction with documented outcomes

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this requirement, so you should treat RS.MA-01 primarily as a defensible-operations control rooted in NIST CSF expectations. (NIST CSWP 29)

Risk implications you can explain to leadership without exaggeration:

• Containment risk: delayed provider action can allow ongoing access or spread.
• Recovery risk: restoration often depends on third-party service owners and support tiers.
• Reporting risk: inaccurate facts flow into customer, partner, insurer, and regulator communications when third-party scope is unknown.
• Evidence risk: failure to request log preservation quickly can limit investigation quality.

Practical 30/60/90-day execution plan

First 30 days (stabilize the basics)

• Define and document incident declaration criteria and authority in the IR plan. (NIST CSWP 29)
• Identify your critical third parties for security operations and core service delivery.
• Create a first version of the third-party coordination register for top incident scenarios.
• Stand up secure communications paths (provider portals, dedicated mailboxes, approved collaboration channels).

Days 31–60 (make it executable)

• Add a Third-Party Liaison role to your incident command model and train alternates.
• Update incident case templates to include third-party notification tasks and evidence fields.
• Review top contracts/support plans for incident cooperation and escalation paths; document gaps and workarounds.
• Run one tabletop that includes third-party coordination steps and produce an after-action report with tracked remediation items.

Days 61–90 (prove operation and close gaps)

• Exercise a second scenario that stresses provider responsiveness (log requests, tenant isolation, credential resets).
• Validate contact rosters and backup contacts with live tests (non-emergency).
• Implement recurring evidence collection: sample incident records or exercise packages that show third-party coordination end-to-end.
• If you use a GRC system, map RS.MA-01 to the policy section, procedure steps, control owner, and an evidence schedule so audits are repeatable. (NIST CSWP 29; NIST CSF 1.1 to 2.0 Core Transition Changes)

Where Daydream fits naturally: If you struggle to keep mappings, owners, and evidence collection consistent across incidents and exercises, Daydream can track RS.MA-01 to the exact plan sections, assign accountable owners, and prompt recurring evidence pulls so you are not rebuilding proof during audits.

Frequently Asked Questions

What counts as a “relevant third party” for RS.MA-01?

Any external party that must take action, provide information, or approve a step to contain, investigate, recover, or communicate once the incident is declared. Relevance is scenario- and asset-dependent, so document it by incident type and system.

Do we need to involve third parties in every incident, even minor ones?

RS.MA-01 triggers “once an incident is declared,” so your declaration criteria matters. If you declare low-severity events as incidents, define a lighter coordination path; otherwise refine criteria so declaration reflects events that require coordinated response.

How do we prove coordination happened during an incident?

Keep time-stamped records: the declaration event, third-party notifications, requests, provider responses, and decisions that depended on third-party input. Link third-party tickets or portal case numbers to your master incident record.

Our cloud provider won’t share certain logs. Are we noncompliant?

Document the limitation, your compensating sources, and escalation steps, and address it in contracting for the next renewal. Auditors look for a deliberate process and evidence of coordination attempts, not perfection.

Should outside counsel be a default third party in the plan?

Include counsel as a predefined option with clear activation triggers (for example, suspected data exposure or regulatory reporting). If you rely on counsel for privilege strategy, pre-arrange engagement so activation is not blocked during an incident.

How often should we test third-party coordination?

Test often enough to keep contacts, escalation paths, and evidence collection reliable. If you can’t include third parties directly, run realistic simulations and track gaps to closure in your IR improvement backlog.