SR-6: Supplier Assessments and Reviews

SR-6 sits in NIST SP 800-53’s Supply Chain Risk Management (SR) family and forces a practical discipline: you cannot treat third-party risk as a one-time onboarding questionnaire. You have to re-assess supply chain-related risks over time, and you must anchor those risks to what the third party actually provides to your environment. That “system, component, or service” anchor is where most programs break down in audits: teams can show a vendor file, but they cannot show how the vendor’s deliverable maps to criticality, data exposure, connectivity, or downstream dependencies.

For a Compliance Officer, CCO, or GRC lead, SR-6 is a control you can operationalize quickly if you make three decisions early: (1) what counts as a “supplier/contractor” in your program, (2) what “supply chain-related risk” means in your business context, and (3) what events force a review beyond the normal cycle. Once those are set, the rest is execution mechanics: inventory, tiering, assessment procedures, review workflows, and durable evidence.

SR-6: supplier assessments and reviews requirement (plain-English meaning)

You must assess and review supply chain-related risks for each supplier or contractor and for the specific system, system component, or system service they provide. The output has to be actionable: risk acceptance, risk treatment requirements, contract controls, or offboarding decisions.

In practice, SR-6 breaks into two motions:

1. Assess: perform an initial supply chain risk assessment before (or at) onboarding and before relying on the third party’s product/service in production.
2. Review: repeat the assessment on a defined cadence and whenever meaningful change occurs (supplier change, product changes, incidents, acquisition, critical subcontractor change, or scope expansion).

This is a supply chain control, so “risk” includes security and resilience, but also provenance, integrity, upstream dependencies, and your ability to detect/contain supplier-driven impact.

Regulatory text

NIST SP 800-53 states: “Assess and review the supply chain-related risks associated with suppliers or contractors and the system, system component, or system service they provide {{ insert: param, sr-06_odp }}.” ¹

Operator translation:

• “Assess and review” means you need an initial assessment plus recurring and event-driven reassessments, not a single point-in-time check.
• “Supply chain-related risks” means evaluate supplier-originating risks such as product integrity, delivery pipeline exposure, upstream subcontractors, and concentration/availability risks relevant to the service.
• “Associated with… the system/component/service they provide” means your assessment record must specify exactly what they provide and how it is used in your environment (where it connects, what data it touches, what privileges it has, what mission/business process it supports).

Reference: NIST SP 800-53 Rev. 5 ²

Who it applies to

Entities

• Federal information systems implementing NIST SP 800-53 controls.
• Contractors handling federal data where NIST SP 800-53 is flowed down via contract, ATO boundary requirements, or customer security requirements. ²

Operational context (where SR-6 shows up in real programs)

• SaaS, cloud hosting, and managed service providers supporting regulated workloads.
• Systems with external components: commercial software, open-source dependencies packaged into products, hardware, firmware, or outsourced development.
• Any environment with privileged third parties (monitoring agents, EDR, backups, CI/CD, payment processors, identity providers).

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

1) Assign ownership and define the SR-6 procedure

• Name a control owner (often Third-Party Risk, Security GRC, or Supply Chain Risk).
• Publish a short SR-6 operating procedure: intake, tiering, assessment method, approval steps, review triggers, and evidence retention.
• Map SR-6 to recurring evidence artifacts so you can answer “show me” requests fast. ¹

Practical tip: Put the procedure where procurement and security both see it (your GRC system or procurement playbook). SR-6 fails when assessments are “owned” by one team but initiated by another.

2) Build a supplier-to-service inventory (the anchor)

Create or fix your inventory so each third party record includes:

• The system/component/service provided (e.g., “CI/CD pipeline service,” “endpoint agent,” “payment gateway,” “laptop fleet,” “firmware module”).
• Where it is deployed (systems, environments, business units).
• Data types accessed/processed/stored and connectivity model (API, agent, SSO, network).
• Privilege level (admin, read-only, break-glass).
• Key subcontractors (if known) and hosting locations (if relevant to your program).

This inventory is the foundation for defensible scoping and reassessment triggers.

3) Tier suppliers by supply chain risk, not spend

Define tiers based on exposure:

• Critical: supplier compromise could directly impact mission/business-critical services, integrity of builds, identity, or broad endpoints.
• High: sensitive data exposure or elevated privilege, but more contained blast radius.
• Standard/Low: limited access, low privilege, easy replacement.

Use a simple decision matrix. Example criteria you can score qualitatively:

• Access to production systems or admin functions
• Ability to push code/updates or run agents
• Direct handling of sensitive data
• Dependency concentration (single supplier for a core function)

4) Define review triggers (event-driven reassessment)

Write down triggers that force an out-of-cycle review, such as:

• Scope change: new data types, new integrations, expanded privileges
• Material product change: new major version, new hosting model, new cryptography model
• Supplier incident affecting confidentiality/integrity/availability of your environment
• Contract renewal or significant price/term change tied to service scope
• Supplier acquisition, bankruptcy risk signals, or change in key subcontractors

Make these triggers operational by embedding them in procurement and change management workflows (ticket templates, intake forms, renewal checklists).

5) Execute the assessment and document decisions

For each in-scope supplier/service:

• Collect evidence (SOC reports where available, security questionnaire, architecture diagrams, incident history disclosures, SBOM or provenance statements when relevant).
• Perform a supply chain-focused risk analysis tied to the provided system/component/service:
  • Integrity: how updates are built, signed, distributed; how you validate changes
  • Access: identity model, MFA, admin controls, logging, segregation of duties
  • Dependency: subcontractors, hosting providers, open-source dependencies
  • Resilience: backup, DR, operational continuity, support model
• Record a risk decision: approve, approve with conditions (remediation plan), restrict scope, or reject/offboard.
• Convert conditions into trackable requirements: contract addenda, control gaps to remediate, compensating controls you will implement internally, deadlines, and owners.

6) Run recurring reviews and show closure

Recurring reviews must prove two things:

• You revisited the supplier risk in light of current facts (updated attestations, changes, incidents, performance).
• You closed the loop on prior findings (remediation verified or risk accepted by the right authority).

A lightweight but defensible recurring review packet:

• Updated supplier profile (service scope, access, data, dependencies)
• Delta since last review (what changed, why it matters)
• Current risk rating and rationale
• Status of findings and exceptions
• Approval record (who approved, when, under what conditions)

7) Make it auditable in your GRC system (where Daydream fits naturally)

SR-6 evidence tends to sprawl across procurement, security, and engineering. Daydream is valuable when you need:

• A single supplier record tied to systems/components/services
• Automated evidence collection reminders and review workflows
• Audit-ready reporting that shows assess → decide → remediate → re-review

If you already have tooling, the requirement still stands: map SR-6 to a named owner, a repeatable procedure, and recurring artifacts that you can produce on demand. ¹

Required evidence and artifacts to retain

Keep artifacts in a way that you can produce them by supplier and by system/service.

Minimum evidence set (practical, audit-friendly):

• SR-6 procedure (versioned) and control owner assignment
• Supplier/service inventory extract showing system/component/service mapping
• Tiering rationale for each supplier (even if brief)
• Assessment package (questionnaire responses, SOC reports if obtained, diagrams, security addenda, support/DR docs as applicable)
• Risk assessment memo or GRC record: risks identified, rating, decision, approver
• Remediation tracker: findings, owners, due dates, closure evidence
• Reassessment records: cadence reviews plus event-driven reviews with trigger notes
• Exceptions: formal risk acceptance records with expiry and compensating controls

Common exam/audit questions and hangups

Auditors and assessors usually press on these points:

• “Show me the list of suppliers and what each one provides to the system boundary.”
• “How do you decide which suppliers are critical?”
• “What triggers a reassessment besides your normal cycle?”
• “Prove your last review changed something: a contract clause, a compensating control, or an offboarding decision.”
• “Where is the evidence that prior findings were closed or re-approved?”

Hangup: teams can show a SOC report but cannot show the review and decision record tied to the system/service.

Frequent implementation mistakes (and how to avoid them)

1. Assessing the supplier, not the supplied service

• Fix: require every assessment record to name the system/component/service and where it connects.

2. No event-driven reviews

• Fix: hard-code triggers into procurement renewals and change management intake.

3. Findings without closure

• Fix: treat third-party findings like internal vulnerabilities: owner, due date, verification, and re-review.

4. Tiering by spend

• Fix: tier by privilege, data exposure, and ability to impact integrity or availability.

5. Evidence scattered across email

• Fix: centralize in a GRC record per supplier/service; attach key artifacts and link tickets.

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this requirement, so you should treat SR-6 as an assessment-readiness and risk-reduction control rather than a penalty-citation exercise.

Risk implications you can articulate internally:

• Supplier compromise can become an enterprise incident quickly if the supplier has privileged access, update channels, or broad endpoint reach.
• Weak reassessment discipline leads to “silent scope creep”: suppliers accumulate access and data over time without re-approval.

Practical 30/60/90-day execution plan

First 30 days (stabilize the minimum viable SR-6)

• Assign the SR-6 control owner and publish a one-page operating procedure.
• Stand up the supplier-to-service inventory fields (service provided, systems, data, access, privilege).
• Define supplier tiers and review triggers.
• Pick a tracking method for findings and exceptions (GRC tool, ticketing, or Daydream).

By 60 days (execute on the highest-risk slice)

• Identify critical/high suppliers based on access and integrity impact.
• Complete assessments for the highest-risk suppliers first.
• Convert gaps into remediation items and contract requirements.
• Start recurring review records for critical suppliers (even if you are catching up).

By 90 days (prove “review,” not just “assessment”)

• Run at least one event-driven or delta-based reassessment where change occurred (renewal, new integration, incident, scope expansion).
• Produce an audit packet: inventory extract, tiering logic, sample assessment files, remediation closure evidence, and approvals.
• Tune triggers and intake forms based on what slipped through.

Frequently Asked Questions

Does SR-6 require a specific assessment questionnaire or framework?

SR-6 does not prescribe a specific questionnaire in the provided text. Use a method that tests supply chain risks tied to the system/component/service and produces a documented decision you can defend ¹.

What counts as a “supplier” for SR-6?

Treat any third party that provides a system, component, or service used in your environment as in scope, including contractors and service providers ¹. Start with those that touch production, identity, endpoints, build pipelines, or sensitive data.

How do I prove I performed “reviews,” not just initial onboarding?

Keep dated reassessment records that reference what changed since the prior assessment, what you re-evaluated, and the updated decision. Auditors look for deltas, approvals, and closure of prior findings more than long narratives.

Can I rely on a SOC 2 report as my SR-6 assessment?

A SOC report can be an input, but SR-6 expects you to assess supply chain risks for the specific service in your context and document your decision ¹. Add your scope mapping, risk rationale, and required conditions.

How should we handle subcontractors (fourth parties) we cannot fully see?

Document known critical dependencies, require disclosure/notification clauses where feasible, and assess your compensating controls (segmentation, least privilege, monitoring, exit plans). Record the residual risk and the approving authority.

What evidence is “most persuasive” in an assessment?

Evidence that ties supplier controls to your actual integration: architecture diagrams, access listings, security addenda, remediation closure proof, and reassessment notes. The best artifact is a complete thread from assessment to decision to verified follow-up.

Footnotes

1. NIST SP 800-53 Rev. 5 OSCAL JSON

2. NIST SP 800-53 Rev. 5