CMMC Physical Security Requirements
Visitor Logs, Escort Rules, and Walkthrough Evidence
Physical security surprises contractors more than any other CMMC domain. Organizations spend months on network architecture and SSP documentation — and then an assessor watches a delivery driver walk unescorted through the loading dock.
The CMMC Physical Protection (PE) domain covers six practices from NIST SP 800-171: limiting physical access, escorting visitors, maintaining physical access logs, managing access devices, monitoring the facility, and safeguarding alternate work sites. All six apply to every location where CUI is present — office, lab, warehouse, or home office.
The Six Physical Protection Practices at a Glance
Maintain a documented authorized access list. Enforce it with locked doors, cipher locks, or badge readers. Cross-reference with your logical access list — if only four people handle CUI, four people should have physical access to the CUI room.
Every non-authorized visitor in a non-public area must be escorted and monitored. This includes delivery personnel, vendors, and subcontractors. Visitor badges identify unescorted individuals in common areas.
Maintain audit records of who enters and exits restricted areas. Paper sign-in sheets, badge reader exports, and digital visitor management systems all qualify. The log must cover every entry point — not just the front desk.
Inventory every key, badge, and cipher code. Document who holds each device. Change codes and retrieve keys when employees leave. Keep the history of those changes — assessors will ask for it.
Install and actively monitor security cameras covering CUI room entry points. Retain recordings per policy. Secure the recording server — it is now an in-scope asset that must be inventoried and documented in your SSP.
CUI at home offices requires documented physical safeguards. Acceptable Use Policy must address workspace privacy and device security. Evaluated through policy review and employee interviews.
Physical Security Evidence: The Examine / Interview / Test Matrix
| Control | Examine | Interview | Test |
|---|---|---|---|
| PE.L1-3.10.1 Limit Access |
Physical access policy; authorized access list; termination/transfer records showing access revoked | Who is on the authorized access list? How is it updated when someone transfers or is terminated? | Verify a recently terminated employee's badge/key has been revoked — attempt access using old credentials |
| PE.L1-3.10.3 Escort Visitors |
Visitor escort policy; visitor log entries showing escort assignment; visitor badge issuance records | Walk the assessor through your visitor arrival process — from front desk sign-in through escort assignment | Observe a visitor reception scenario; verify delivery personnel entering via alternate entrances are also escorted |
| PE.L1-3.10.4 Access Logs |
Physical access log (paper or digital); badge reader exports showing entry/exit timestamps | Who reviews the access logs? How often? What happens if an anomaly is detected? | Attempt an unauthorized entry and verify the attempt is logged; confirm logs are protected from tampering |
| PE.L1-3.10.5 Access Devices |
Key/badge inventory showing who holds each device; issuance and return records; code change history | What is the process when an employee leaves — how are keys, badges, and codes recovered or changed? | Verify the key/badge inventory matches current authorized personnel; confirm codes were changed after last termination |
| PE.L2-3.10.2 Monitor Facility |
Camera deployment policy; coverage diagram; recording retention schedule; secured DVR location | Who monitors cameras and how often? Where are recordings stored and who has access? | Verify camera recordings are stored in a secured location accessible only to authorized personnel |
| PE.L2-3.10.6 Alternate Sites |
Remote work policy; AUP for home offices; physical controls documentation | How does the policy address physical CUI protection at home offices? What are employee obligations? | Review a sample of remote employees — confirm CUI devices are not accessible to family members or visitors |
The Window Trap and Other Boundary Failures
The door control passes. The physical boundary fails. CMMC requires that CUI cannot be visually accessed by unauthorized individuals — not just that they cannot physically enter.
Frosted window film — blocks line of sight while preserving light
Privacy screens on monitors facing windows or openings
Opaque partitions replacing transparent glass walls
Monitor repositioning so screens face away from observation points
Five Common Failures That Derail Assessments
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Unescorted Loading Dock
A perfect front lobby log means nothing if delivery drivers enter through the back unescorted. All entry points — including loading docks, emergency exits, and vendor entrances — must be covered.
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Window Trap
A cipher lock on the door does not protect CUI if an unauthorized employee can look through a glass window and read a monitor. Windows must be frosted, blocked, or monitors repositioned.
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Missing Placards
CUI rooms must have clearly visible warning indicators at the entrance. Assessors confirm this during the walkthrough — missing or hidden placards are immediate findings.
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Camera Recording Server
The DVR or NVR storing security footage is an in-scope asset. It must be access-controlled, inventoried, and documented in the SSP — just like any other CUI-adjacent system.
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Printers in Common Areas
Output devices that can print CUI must be physically restricted. A printer in an open break room visible to unauthorized personnel is a physical boundary failure, regardless of access controls on the print queue.
Walkthrough Strategy: Consistency Between Policy and Practice
Whether conducted on-site or by live video, the walkthrough tests whether your SSP matches your facility. Brief your walkthrough guide on every camera angle, cipher lock location, placard placement, and visitor log position. An unprepared guide signals poor control awareness — even if every control is actually in place.
Frequently Asked Questions
The Bottom Line
Physical protection is not a checkbox. It is evaluated with the same rigor as every technical control, and it is verified against what an assessor sees — not just what the SSP describes.
Walk every entry point, cover every window, post every placard, document every key and code change, and make sure your walkthrough guide knows the facility as well as the assessor will by the end of day one.
Paper policy without physical reality is a guaranteed finding. Document it, implement it, walk it — and make sure what the assessor sees matches what the SSP says.