CMMC requires physical access to systems containing or transmitting CUI to be limited to authorized individuals and for access records to be maintained. Badge readers with unique identification provide individual accountability, access control enforcement, and auditable access logs, which are stronger than labels, cameras, or keypads.

Exact Extracts:

PE.L2-3.10.1: “Limit physical access to organizational systems, equipment, and the respective operating environments to authorized individuals.”

PE.L2-3.10.5: “Maintain audit logs of physical access.”

CMMC Assessment Guide: “Badge systems with access control lists and logs are considered a best method for meeting physical access requirements.”

Why the other options are not correct:

A: Labels and lists do not prevent unauthorized access.

C: Cameras monitor but do not restrict access; they are detective, not preventive.

D: Keypads do not provide individual accountability (codes can be shared).