03.08.01: Media Storage

To meet the 03.08.01: media storage requirement, you must control where and how CUI-bearing media is stored so it remains protected throughout its lifecycle, including removable media, backups, and offline archives. Operationalize it by inventorying media types, defining approved storage locations and protections, and collecting repeatable evidence that storage controls work. ¹

Key takeaways:

• Define “media” broadly (removable drives, backup tapes, offline archives, exported files) and treat storage as a controlled state, not a convenience.
• Standardize approved storage locations, encryption/physical protections, and access rules for CUI-bearing media.
• Build evidence you can show quickly: inventories, storage standards, access logs, and exception approvals. ¹

03.08.01 sits in the “Media Protection” family of NIST SP 800-171 and is routinely tripped by otherwise mature programs because it spans both IT and physical operations. “Media storage” is where process gaps show up: a backup drive in a desk drawer, a NAS share used as an “archive,” a contractor shipping data on removable media, or exports of CUI to spreadsheets stored in unmanaged locations.

For a CCO, GRC lead, or control owner, the fastest path is to treat media storage as a defined control surface with three components: (1) scope (what counts as media, what counts as CUI-bearing), (2) standard storage requirements (where it may be stored, with what protections), and (3) proof (artifacts that show the standard is followed and exceptions are managed). This page gives requirement-level implementation guidance you can assign to IT, Security, and Records/Facilities, then validate during internal review or an assessment against NIST SP 800-171 Rev. 3. ¹

Regulatory text

Requirement: “NIST SP 800-171 Rev. 3 requirement 03.08.01 (Media Storage).” ¹

Operator interpretation: You must define and enforce how media that contains CUI is stored so it is protected against unauthorized access, loss, or compromise while at rest. “Media” includes physical and digital storage forms, and “stored” includes short-term staging and long-term retention. Your assessor will expect consistent rules (policy/standard), technical and physical controls that match those rules, and auditable evidence that the controls are working. ¹

Plain-English interpretation (what 03.08.01 means day-to-day)

If a human can walk off with it, mail it, misplace it, or copy it, you need storage rules. If a system can replicate it into backups, exports, or offline archives, you need storage rules there too. 03.08.01 is satisfied when:

• You know what media can contain CUI (and you can find it).
• You restrict where that media is allowed to live.
• You apply protections appropriate to the medium (encryption, locked storage, controlled access, environmental safeguards as relevant).
• You manage exceptions, and you can prove it with repeatable artifacts. ¹

Who it applies to

Entities

• Federal contractors and other organizations operating nonfederal systems that handle CUI under NIST SP 800-171 requirements. ¹

Operational contexts (where this shows up)

• End-user endpoints: laptops/desktops that download, sync, or export CUI.
• Removable media: USB drives, external HDD/SSD, SD cards, optical media.
• Backup and recovery: backup appliances, tapes, snapshots, offline backups, “air-gapped” copies.
• File services and collaboration: network shares, document repositories, secure file transfer staging.
• Physical records and mixed media: printed CUI, scanned images, DVDs, engineering drawings.
• Third parties: MSPs, backup providers, eDiscovery firms, shipping/courier services that handle media containing CUI.

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

Use this sequence to get compliant fast and stay assessment-ready.

1) Define scope: “media” and “CUI-bearing”

1. Write a media definition for your environment that explicitly includes removable media, backup media, and offline archives.
2. Define CUI-bearing media as any media that stores, processes, or transmits CUI, including derived outputs (exports, reports, logs if they contain CUI).
3. Set the rule: CUI-bearing media must only be stored in approved locations with required protections. ¹

Deliverable: Media Storage Standard (one to two pages) mapped to 03.08.01.

2) Build and maintain an inventory of storage media classes and locations

1. Identify media classes you allow (for example: encrypted USB only, approved backup vault only).
2. Identify media locations you operate (server rooms, secure cabinets, offsite storage, backup cages).
3. Assign an owner to each class/location (IT, Security, Facilities, Records).
4. Record how you will detect drift (endpoint management, backup console reports, physical sign-out logs).

Deliverable: Media inventory register and ownership list.

3) Establish approved storage requirements by media type

Create a simple matrix so teams can execute without interpreting policy every time.

Example control matrix (tailor to your environment):

Media type	Approved storage locations	Minimum protections (examples)	Access control expectation	Exception path
Removable USB/external drives	Secured cabinet when not in use	Encryption required; labeled and tracked	Issued to named custodian	Written approval + return date
Backup media (tape/offline)	Locked vault / controlled data center area	Physical controls; tamper-evident handling if used	Limited admin group	Change record + risk acceptance
Printed CUI	Locked office/cabinet	Physical locks; clean desk rules	Need-to-know	Records manager approval
Endpoint local storage	Managed endpoints only	Full-disk encryption; device control	Role-based access	Security exception ticket

Your exact protections will depend on system design, but the assessor will expect that you chose safeguards appropriate to the storage risk and that they are consistently applied. ¹

Deliverable: Media Storage Control Matrix referenced by policy/standard.

4) Implement technical controls that enforce the storage standard

Typical implementation actions (select what fits your environment):

• Device control / endpoint management: restrict or audit removable media use; require encryption where supported.
• Encryption at rest: ensure endpoints and portable media storing CUI are encrypted according to your standard.
• Access control and logging: limit admin and user access to backup repositories and archives; enable logs that show who accessed what and when.
• Data loss prevention (if available): prevent copying CUI to unapproved destinations, or alert and ticket exceptions.
• Backup configuration hardening: confirm backup sets containing CUI are stored only in approved repositories and retention aligns to your records rules.

Deliverable: Configuration baselines, screenshots/exports, and control settings documentation tied to your matrix.

5) Implement physical controls for offline and tangible media

• Restrict storage areas (locks, badges, visitor controls) for rooms/cabinets holding CUI-bearing media.
• Maintain a media check-in/check-out process for removable/offline media.
• Define handling requirements for transport and offsite storage when used, including chain-of-custody expectations aligned to your risk.

Deliverable: Physical security procedure + sign-out logs + storage location list.

6) Manage exceptions like a product, not a favor

Exceptions are where auditors focus.

• Require a ticket with: media type, CUI type, reason, duration, compensating controls, approving authority.
• Time-bound approvals and require return/disposition confirmation.
• Track exception volume and recurring causes, then fix root issues (procurement, tooling gaps, unclear requirements).

Deliverable: Exception register and sample approvals.

7) Put evidence collection on a schedule (recurring and lightweight)

03.08.01 often fails in practice due to “we did it once” documentation. Build repeatable evidence capture:

• Periodic export from endpoint management showing encryption status and removable media controls.
• Periodic backup console report showing backup storage locations and access restrictions.
• Periodic review of physical sign-out logs and spot checks of storage areas.
• Exception report and closure evidence.

Daydream can help here by mapping 03.08.01 to your policy/control owners and generating an evidence request cadence so you are not rebuilding proof during assessment season. ¹

Required evidence and artifacts to retain

Keep artifacts that prove both design and operation:

Design evidence

• Media Storage Policy/Standard mapped to 03.08.01.
• Media Storage Control Matrix (approved media types, locations, protections).
• Data classification/CUI handling standard that ties to media rules.
• Roles/responsibilities (RACI) for IT, Security, Facilities, Records.

Operational evidence

• Media inventory register (including offline/backup media where applicable).
• Endpoint encryption/device-control reports or screenshots/exports.
• Backup configuration exports (storage targets, retention, access roles).
• Access control lists or role assignments for backup repositories.
• Physical media sign-out logs; visitor logs for secure areas (as applicable).
• Exception tickets with approvals and closure proof.

Common exam/audit questions and hangups

Expect questions like:

• “Show me where CUI is stored on media, including backups and offline archives.”
• “What removable media is permitted, and how do you enforce encryption?”
• “How do you prevent staff or third parties from storing CUI on unapproved media?”
• “Prove this is operating, not just written.” Provide exports/logs and a sample of exceptions with approvals.

Common hangups:

• Teams document endpoint encryption but ignore backup media and exported files.
• Facilities controls exist, but there is no linkage showing the room/cabinet contains CUI-bearing media.
• Exceptions are informal (email approvals) and can’t be summarized cleanly.

Frequent implementation mistakes (and how to avoid them)

1. Mistake: Treating “media” as only USB drives.
   Fix: Include backup storage, offline archives, printed material, and staging areas in your definition and inventory. ¹

2. Mistake: No clear “approved locations” list.
   Fix: Publish an explicit allowlist (repositories, cabinets, vaults) and route everything else through exceptions.

3. Mistake: No operational evidence.
   Fix: Automate evidence pulls from endpoint/backup tools and store them with dates and owners. Daydream-style evidence workflows reduce scramble during assessments. ¹

4. Mistake: Third parties handling media without your storage rules.
   Fix: Add contract language and due diligence steps for third parties that store or transport CUI-bearing media, then collect their attestations and procedural docs.

Risk implications (why assessors care)

Media storage failures are high-impact because they create loss scenarios that bypass strong perimeter controls: lost drives, mishandled backups, or exported datasets in uncontrolled locations. The operational risk includes breach notification exposure, contract noncompliance, and inability to demonstrate adequate protection of CUI during audits against NIST SP 800-171 Rev. 3. ¹

Practical execution plan (30/60/90)

First 30 days (stabilize and define)

• Name control owner(s) across IT/Security/Facilities/Records.
• Publish a Media Storage Standard with a clear media definition and “approved storage” rule.
• Build the initial media/storage inventory (include backup and offline media).
• Stand up an exception workflow with approval authority.

By 60 days (implement and enforce)

• Configure endpoint and backup tooling to align to the storage matrix (encryption, access controls, logging where applicable).
• Implement physical storage controls (locked cabinets/rooms, sign-out logs).
• Update third-party requirements where they store/handle CUI-bearing media.

By 90 days (prove operations and close gaps)

• Run an internal control test: select samples of media types and prove storage compliance end-to-end.
• Produce an evidence packet (reports, logs, tickets) and fix missing telemetry or unclear procedures.
• Operationalize recurring evidence collection in your GRC workflow (Daydream or equivalent) so 03.08.01 stays current. ¹

Frequently Asked Questions

Does 03.08.01 apply to cloud storage or only physical media?

It applies to any storage medium that can hold CUI, including cloud repositories and backups, if they function as media storage in your environment. Your job is to define approved storage locations and protections and prove they are enforced. ¹

Are backups in scope even if users never touch them?

Yes, because backups are a common place where CUI persists outside primary systems. Treat backup targets, offline copies, and archive tiers as media storage locations with defined protections and access controls. ¹

What’s the minimum evidence an assessor will accept?

A written standard tied to 03.08.01, an inventory of media/storage locations, and operational proof (tooling exports/logs and a few exception tickets). If you can’t show repeatable operation, the control is likely to be scored as weak. ¹

We ban USB drives. Are we done?

Not by itself. You still need to cover other media forms such as offline backups, printed CUI, and exports stored on endpoints or file shares, plus evidence that the ban is enforced. ¹

How do we handle contractors or other third parties who need to move data?

Require secure, approved transfer and storage methods in contracts and procedures, and prohibit ad hoc removable media unless formally approved as an exception. Keep chain-of-custody style records when physical media is involved. ¹

What should we do if we discover CUI on unapproved media?

Treat it as an incident or control breach under your governance process: contain, migrate to approved storage, document corrective actions, and determine whether an exception is justified or the process needs tightening. Preserve evidence of remediation for assessment readiness. ¹

Footnotes

1. NIST SP 800-171 Rev. 3