IA-4(6): Cross-organization Management

IA-4(6): cross-organization management requirement means you must coordinate with specified external organizations to manage identifiers consistently across organizational boundaries (for example, partner directories, federated identity, shared services, or mission partners). Operationalize it by documenting who you coordinate with, what identifier rules you share, how changes are approved, and what evidence proves the coordination happens. ¹

Key takeaways:

• Define the external organizations in scope and the identifier “contract” you will enforce across boundaries. ¹
• Build repeatable coordination steps: request, approve, implement, validate, and record identifier changes across organizations. ¹
• Keep assessor-ready artifacts: agreements, procedures, logs/tickets, and periodic reconciliation results. ¹

Cross-organization identity is where clean internal IAM practices often break: two organizations connect systems, exchange attributes, or honor each other’s accounts, and suddenly identifier collisions, ambiguous naming, orphaned partner accounts, and inconsistent deprovisioning become real risks. IA-4(6) exists to force disciplined coordination so identifiers stay unique, traceable, and manageable when more than one organization participates in identity lifecycle decisions.

For a CCO or GRC lead, the fastest path is to treat IA-4(6) as a governance-and-evidence control. You are not being asked to “deploy a product.” You are being asked to prove that your program coordinates with specific external organizations on how identifiers are created, formatted, changed, linked to people/services, and retired. The control’s hard part is scoping and repeatability: naming the external organizations, documenting the coordination mechanism, and retaining artifacts that show it runs as designed.

This page gives requirement-level implementation guidance you can hand to IAM, security engineering, and partner management teams to execute quickly, with a clear evidence list for assessments against NIST SP 800-53 Rev. 5. ²

Regulatory text

Control requirement (verbatim): “Coordinate with the following external organizations for cross-organization management of identifiers: {{ insert: param, ia-04.06_odp }}.” ¹

What the operator must do with this text

1. Fill in the parameter. The “external organizations” are not implied; your system/security plan (or equivalent control statement) must explicitly list the external organizations you coordinate with for identifier management. ¹
2. Define “coordinate” in operational terms. An assessor will look for a repeatable mechanism: agreed rules, documented handoffs, and records of actions taken. A calendar meeting with no decisions or artifacts rarely holds up. ¹
3. Scope to identifiers, not authentication strength. IA-4 is about identifier management. MFA and federation security matter, but IA-4(6) specifically expects cross-organization alignment on the identifier lifecycle. ¹

Plain-English interpretation (what IA-4(6) is really asking)

You must prevent identifier confusion across organizational boundaries. If you accept identities from a third party (customer/partner IdP, shared directory, government enterprise identity, subcontractor workforce system), you need shared rules that answer:

• What counts as a unique identifier across both organizations (format, namespace, uniqueness rules).
• How identifiers map to real-world subjects (person, service account, device, workload).
• Who can create/change/disable identifiers and how the other organization is notified.
• How you handle collisions, merges, rehires, and role changes when identity signals come from outside your control.

Treat this as a “joint lifecycle contract” for identifiers and evidence that you execute it. ¹

Who it applies to (entity and operational context)

IA-4(6) commonly applies where your system interacts with external identity sources or where identifiers are managed jointly with third parties. This includes:

In-scope entities

• Federal information systems implementing NIST SP 800-53 controls. ²
• Contractor systems handling federal data where NIST SP 800-53 is contractually required or used for assessment baselines. ²

In-scope operational contexts (what assessors will focus on)

• Federated SSO (SAML/OIDC) with partners, customers, or government identity providers.
• Shared services (managed SOC tooling, shared ticketing, shared HR feeds) that create or influence accounts.
• B2B integrations where user identifiers are transmitted (SCIM provisioning, API user IDs, directory sync).
• Subcontractor/third-party workforce access into your environment.

If there is no cross-organization identity relationship, document that determination with a short scoping memo and revisit it when onboarding new third parties. ¹

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

Step 1: Identify and name the external organizations (your IA-4(6) list)

Create a definitive list of external organizations that affect identifiers for your system:

• Partner/customer identity providers that authenticate users into your system
• Organizations that provision accounts into your directory/application
• Organizations where you provision accounts into their systems on behalf of your users

Deliverable: “IA-4(6) external organizations in scope” register, owned by IAM with GRC review. ¹

Step 2: Define the cross-organization identifier rules (“identifier contract”)

For each external organization, write down:

• Identifier types in scope: human user IDs, service accounts, privileged admin IDs, shared accounts (if any), API client IDs.
• Format and namespace rules: allowed characters, uniqueness requirements, case-sensitivity, prefixing, and whether the identifier must be immutable.
• Authoritative source: which organization is system-of-record for each identifier attribute (e.g., subject ID, email, UPN, employee/contractor ID).
• Lifecycle events: create, update, suspend, terminate; include rehire and contractor offboarding edge cases.
• Collision handling: what happens if identifiers overlap or a partner reissues an identifier.

Deliverable: per-third-party “Identifier Management Profile” (a short standard template). ¹

Step 3: Implement a coordination workflow (request → approve → implement → validate)

Build a workflow that works for both security and partner teams:

1. Change request intake: tickets or a shared queue for identifier lifecycle changes tied to a third party relationship.
2. Approval gates: define who approves identifier schema changes, federation subject mappings, and provisioning settings.
3. Implementation steps: documented configuration actions (IdP mapping, SCIM connector changes, directory attribute transformations).
4. Validation: test a sample of accounts for correct identifier creation and deprovisioning behavior after changes.
5. Recordkeeping: attach artifacts to the ticket (screenshots, config diffs, test results, partner confirmation).

This is the control’s make-or-break point: you need repeatable proof of cross-organization coordination, not tribal knowledge. ¹

Step 4: Set reconciliation checks (ongoing operational control)

Run periodic reconciliations that catch drift between organizations:

• Compare active federated users vs active partner roster (where available).
• Review “unknown” identities hitting your apps (unmapped domains/issuers/subject formats).
• Check for duplicate identifiers or mismatched immutable IDs.
• Confirm deprovisioning signals are honored (terminations, contract end dates).

Deliverable: reconciliation report with issues tracked to closure. ¹

Step 5: Assign ownership and keep the control assessable

Minimum roles:

• Control owner: IAM lead or security architecture
• Relationship owner: third-party management / procurement / partner manager
• Evidence owner: GRC

Daydream (or any GRC system) fits naturally here by mapping IA-4(6) to a named owner, a documented procedure, and a recurring evidence checklist so you do not scramble at assessment time. ¹

Required evidence and artifacts to retain

Keep artifacts tied to each external organization in scope:

Artifact	What it proves	Good enough for an assessor
External organization scope register	You identified who you must coordinate with	Named list, system/application mapping, owner
Identifier Management Profile 1	Shared identifier rules and lifecycle agreement	Versioned doc with last review date and approvers
Federation/provisioning diagrams	How identifiers flow across boundaries	Data flow including authoritative sources
Tickets/changes with attachments	Coordination happened and changes were controlled	Partner communications + approvals + test results
Reconciliation reports and issue logs	Ongoing management, drift detection	Findings, remediation actions, closure evidence
Third-party agreements (contract/SOW/ISA) where relevant	Coordination commitments and responsibilities	Clauses/appendix referencing identity/identifier management expectations

Retain evidence in a single control folder per partner, not scattered across email threads. ¹

Common exam/audit questions and hangups

Assessors commonly probe these areas:

1. “Which external organizations are in scope for IA-4(6)?” If you cannot name them, you fail the first test. ¹
2. “Show me how identifier changes are coordinated.” Expect a request-to-implementation trail with approvals and validation. ¹
3. “How do you prevent identifier collisions across organizations?” They want rules plus operational checks. ¹
4. “What happens when a partner terminates a user?” Walk through the deprovisioning path and show evidence it works. ¹
5. “Who owns this control?” “Shared responsibility” without named owners reads as unmanaged. ¹

Frequent implementation mistakes (and how to avoid them)

• Mistake: treating coordination as a meeting. Fix: require a ticketed workflow and version-controlled identifier profiles per external organization. ¹
• Mistake: scoping only to “vendors.” Fix: include customers, mission partners, parent/subsidiaries, and any third party that supplies or consumes identifiers. ¹
• Mistake: relying on email addresses as identifiers. Fix: define stable subject identifiers (immutable IDs) and document mapping rules; emails change. ¹
• Mistake: no drift detection. Fix: run reconciliations and track exceptions to closure. ¹
• Mistake: unclear offboarding responsibilities. Fix: write down who disables access in which system, with time expectations defined in the agreement/procedure as your policy requires. ¹

Enforcement context and risk implications

No public enforcement cases were provided for this requirement in the supplied source material, so this page does not cite enforcement actions.

Risk-wise, weak cross-organization identifier management shows up as:

• Orphaned third-party accounts that remain active after offboarding
• Duplicate identities that bypass segregation-of-duties assumptions
• Misattributed actions in logs because identifiers are inconsistent across systems
• Excessive manual fixes during incidents because identity sources conflict

The practical risk is audit failure plus real access control breakdowns during partner changes, mergers, and emergency access scenarios. ²

Practical 30/60/90-day execution plan

First 30 days (establish scope + minimum documentation)

• Create the external organizations in scope register for the system.
• Assign control owner, evidence owner, and relationship owners.
• Draft the Identifier Management Profile template and complete it for the highest-risk external organization first (privileged access or broad user population). ¹

Days 31–60 (make it operational and repeatable)

• Implement the coordination workflow in your ticketing system with required fields and attachments.
• Capture current-state diagrams of identifier flows (federation and provisioning).
• Run the first reconciliation and open issues for collisions, stale accounts, or unmapped subjects. ¹

Days 61–90 (prove ongoing operation + close gaps)

• Execute at least one real change through the workflow (or document the last change retroactively with artifacts if allowed by your process).
• Close high-severity reconciliation findings and document compensating controls where closure takes longer.
• Package artifacts into an assessor-ready evidence set in Daydream (or your GRC repository): scope register, profiles, tickets, reconciliation reports, and ownership mapping. ¹

Frequently Asked Questions

What counts as an “external organization” for IA-4(6)?

Any third party that creates, asserts, transforms, or consumes identifiers used by your system counts. Common examples include federated identity providers, managed service providers provisioning accounts, and mission partners with shared directories. ¹

Do we need a contract clause to satisfy IA-4(6)?

The control requires coordination, not a specific contract format. A contract clause helps, but you can also meet the requirement with documented procedures, agreed identifier profiles, and recorded coordination activities. ¹

If we use SAML/OIDC federation, is that automatically compliant?

No. Federation is a technical mechanism; IA-4(6) expects managed coordination about identifier formats, lifecycle, and change control across organizations, plus evidence. ¹

What evidence is strongest for auditors?

Versioned identifier management profiles plus tickets that show cross-organization requests, approvals, implementation proof, and validation results tend to be the most persuasive. Add periodic reconciliation reports to show ongoing management. ¹

How do we scope IA-4(6) if we have many partners?

Start with partners that provision identities or grant broad access, then expand to the rest using a consistent template. Keep the partner list explicit and reviewed as part of third-party onboarding so scope stays current. ¹

Who should own IA-4(6) in a three-lines-of-defense model?

Put day-to-day ownership with IAM/security engineering, and assign GRC to define evidence requirements and test operation. Third-party relationship owners should be accountable for ensuring partners follow the identifier profile and workflow. ¹

Footnotes

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

2. NIST SP 800-53 Rev. 5