Identification
Identify system users, processes acting on behalf of users, and devices.
What gets scored, the objectives
IA.L2-3.5.1 is met only when every one of these 3 objectives, from NIST SP 800-171A, is satisfied. A single missed objective makes the whole requirement not met.
- a.system users are identified
- b.processes acting on behalf of users are identified
- c.devices accessing the system are identified
How this is assessed
NIST SP 800-171A defines three assessment methods. For IA.L2-3.5.1, whoever assesses it, including your own team in a self assessment, uses these:
Identification and authentication policy; procedures addressing user identification and authentication; system security plan, system design documentation; system configuration settings and associated documentation; system audit logs and records; list of system accounts; other relevant documents or records
Personnel with system operations responsibilities; personnel with information security responsibilities; system or network administrators; personnel with account management responsibilities; system developers
Organizational processes for uniquely identifying and authenticating users; mechanisms supporting or implementing identification and authentication capability
What it means, in context
Common device identifiers include media access control (MAC), Internet Protocol (IP) addresses, or device-unique token identifiers . Management of individual identifiers is not applicable to shared system accounts . Typically, individual identifiers are the user names associated with the system accounts assigned to those individuals . Organizations may require unique identification of individuals in group accounts or for detailed accountability of individual activity. In addition, this requirement addresses individual identifiers that are not necessarily associated with system accounts . Organizational devices requiring identification may be defined by type, by device, or by a combination of type/device. NIST SP 800-63-3 provides guidance on digital identities.
Make sure to assign individual, unique identifiers (e.g., user names) to all users and processes that access company systems . Authorized devices also should have unique identifiers. Unique identifiers can be as simple as a short set of alphanumeric characters (e.g., SW001 could refer to a network switch, SW002 could refer to a different network switch). This requirement, IA.L2-3.5.1, provides a vetted and trusted identity that supports the access control mechanism required by AC.L2-3.1.1. Example You want to make sure that all employees working on a project can access important information about it. Because this is work for the DoD and may contain CUI, you also need to prevent employees who are not working on that project from being able to access the information. You assign each employee is assigned a unique user ID, which they use to log into the system [a].
What passing evidence looks like
The user, process, and device identifier scheme in one short note (naming convention, service account naming, device naming) and the directory screenshots showing it in force.
Common ways contractors fail IA.L2-3.5.1
- !Devices need identity too. Registered or joined devices in the directory, or at least a named device inventory, answers the device half most shops forget.
The step by step walkthrough for Microsoft 365 GCC High, Google Workspace, and on premises setups, plus the exact evidence to capture, lives inside the CMMC Level 2 plan.
Prove IA.L2-3.5.1, and the other 109
The Level 2 workspace walks your team through all 110 requirements at the objective level, drafts your SSP section by section from your own record for your team to read and accept, gives a prime or your own internal auditor a read only seat on the same record, and a credentialed officer reviews every step.
Book a free advisory callNo credit card, and Level 1 and Level 2 are both open, so sign up for the level your contracts call for. Self assessed and self attested: you score yourself in SPRS on a three year cycle and your senior official affirms it every year. As of September 3, 2026 a class deviation directs contracting officers to remove third party assessment from contracts. The program rule still provides for it, so your solicitation sets the track. Your team builds the same evidence either way. DFARS 252.204-7012 is unaffected, and the NIST SP 800-171 Rev 2 baseline is unchanged.
IA.L2-3.5.1 questions, answered
How many points is CMMC requirement IA.L2-3.5.1 worth?+
IA.L2-3.5.1 is worth 5 points in the CMMC Level 2 score under 32 CFR 170.24. If it is not met, you lose 5 from your total of 110.
Can IA.L2-3.5.1 be placed on a POA&M?+
No. IA.L2-3.5.1 must be fully met before you can file. It cannot be deferred to a POA&M, so it is a gate on your assessment.
What family does IA.L2-3.5.1 belong to?+
IA.L2-3.5.1 is in the Identification & Authentication (IA) family, one of the 14 families of NIST SP 800-171 that make up CMMC Level 2.
- NIST SP 800-171 Rev. 2 3.5.1
- FAR Clause 52.204-21 b.1.v