What this requirement asks
Prevent reuse of identifiers for a defined period.
This is a CMMC Level 2 requirement in the Identification & Authentication family, drawn from NIST SP 800-171 Rev. 2. An assessor evaluates it objective by objective — every objective below must be supported by evidence, not just described in a policy.
Assessment objectives (2)
- 3.5.5[a] — a period within which identifiers cannot be reused is defined
- 3.5.5[b] — reuse of identifiers is prevented within the defined period
What an assessor examines
Examine:
- Identification and authentication policy
- system security plan
- procedures addressing authenticator management
- procedures addressing user identification and authentication
- system design documentation
- list of system authenticator types
- system configuration settings and associated documentation
- change control records associated with managing system authenticators
- system audit logs and records
- other relevant documents or records
Interview:
- Personnel with authenticator management responsibilities
- personnel with information security responsibilities
- system or network administrators
Test:
- Mechanisms supporting or implementing authenticator management capability
Evidence that defends it
Show conditional access/rules
Check your readiness
Score this requirement against your own environment with the Level 2 self-assessment checklist, or estimate your SPRS score with the free CMMC compliance tool. Self-reported answers are planning signals only — they do not establish a verified or assessor-accepted result.