User Identification, Authentication, and Re-Authentication is the first requirement in the Identification and Authentication (03.05) family, and it establishes the baseline that every access decision depends on. Account Management (03.01.01) decides who gets an account, and User Identification, Authentication, and Re-Authentication (03.05.01) makes sure the system can uniquely tell who is who and confirm it. It has two (2) parts: uniquely identify and authenticate system users and associate that unique identity with processes acting on their behalf, and re-authenticate users when defined circumstances occur. Per the NIST discussion, unique identification and authentication apply to all system accesses, organizations may re-authenticate when roles, authenticators, or credentials change, when privileged functions execute, or after a fixed time period.
A common difficulty with this requirement is the re-authentication half, which is new for R3. Unique identification and authentication were already expected under R2, but the explicit requirement to re-authenticate under defined circumstances is new, and the circumstances themselves are an Organization-Defined Parameter (ODP). Shared or generic accounts are the other common failure, since they break the unique-identification objective.
Where things stand for companies facing the transition from NIST 800-171 R2 to R3:
The following is reproduced verbatim from NIST 800-171 R3, requirement 03.05.01 User Identification, Authentication, and Re-Authentication. Only the formatting has been adjusted for readability. This requirement has two (2) lettered parts:
The source controls are IA-02 and IA-11 from NIST 800-53. The bracketed assignment in part b is the Organization-Defined Parameter (ODP): the circumstances or situations requiring re-authentication. Per the NIST discussion, organizations use passwords, physical authenticators, biometrics, or a combination to authenticate identities, and unique identification and authentication apply to all system accesses. You can read the requirement directly at NIST 800-171 R3, 03.05.01 (p. 33).
One (1) value sits inside this requirement. Depending on your contract, your organization may be permitted to define it. Organizations in the DIB subject to CMMC are not, because the DoD has defined it as policy.
The value below comes from Attachment A of the DoD Chief Information Officer (CIO) memorandum dated 10 April 2025 (signed David W. McKeown). The memo identifies each parameter by requirement sub-part, while NIST 800-171A R3 identifies the same parameter by ODP number. Both identifiers appear below so you can match your System Security Plan (SSP) language to either document.
The memo states that its values "will be updated as necessary," so confirm against the current version before writing them into policy.
NIST 800-171A R3 breaks 03.05.01 into five (5) assessment objectives: one (1) Organization-Defined Parameter (ODP) and four (4) determination statements. These AOs are:
Part a splits into unique identification, authentication, and associating processes with the authenticated user. If you are a DoD contractor, the ODP is specified. Per the DoD-specified ODP value in ComplianceForge's NIST 800-171 R3 Transition Guide, re-authentication is required when roles, authenticators, or credentials change, including a modification of user privilege, when the security categories of systems change, when privileged functions execute, and after a session termination. The full guidance on assessment methods and objects, is in NIST 800-171A R3, 03.05.01 (p. 42).
Examine: identification and authentication policy and procedures; list of circumstances or situations requiring re-authentication; system design documentation; system configuration settings; system audit records; list of system accounts; system security plan.
Interview: personnel with identification and authentication responsibilities; personnel with system operations responsibilities; personnel with account management responsibilities; system developers; personnel with information security responsibilities; system administrators.
Test: processes for uniquely identifying and authenticating users; mechanisms for supporting or implementing identification and authentication capabilities.
03.05.01 maps from NIST 800-171 R2 requirement 3.5.1 (identify system users, processes acting on behalf of users, and devices), and it draws on R2 requirement 3.5.2 (authenticate the identities of users, processes, or devices as a prerequisite to allowing access):
Mapped against the five (5) AOs, two (2) are direct (minimal effort), one (1) is indirect (moderate effort), one (1) is net new, and one (1) has no clear mapping, with the last two (2) categories both counting as significant effort. Identification and authentication carry forward, but the re-authentication objective and its parameter are the new work. The unique-identification requirement also matters more in R3, so confirm that shared and generic accounts are not undermining it.
Source Controls in NIST 800-53 R5:
Secure Controls Framework (SCF) Crosswalk
Organizations running a single control set across multiple frameworks can satisfy 03.05.01 through the following SCF controls:
The crosswalks from NIST 800-171 R3 and NIST 800-171A R3 to the SCF are available at no cost through the SCF Set Theory Relationship Mapping (STRM): https://securecontrolsframework.com/start-here/set-theory-relationship-mapping-strm. The STRM also carries the relationship type for each mapping (Equal, Subset Of, Intersects With), which tells you whether an SCF control fully satisfies the requirement or only part of it. Mapping above taken from SCF 2026.3.
The following are issues teams may encounter rather than certainties. They are about re-authentication and unique identity, each of which needs documented evidence of due diligence and due care such as policies, standards, procedures, and configuration screenshots:
Reasonable objective evidence for an assessment is often subjective. The following examples of evidence to address NIST 800-171 R3 03.05.01 are sourced from the SCF Evidence Request List (ERL), available at https://securecontrolsframework.com/free-content/scf-download. These ERL artifacts are mapped to NIST 800-171 R3 03.05.01 through SCF controls. They establish a starting point for discussions on what an organization needs to have for evidence of due diligence and due care to withstand external scrutiny by an assessor or regulator.
Alongside these, keep the System Security Plan (SSP) narrative for 03.05.01 recording the ODP values you adopted.
With two (2) AOs mapping directly, one indirectly, one net new, and one with no clear mapping, 03.05.01 is a moderate lift concentrated on re-authentication. A realistic sequence:
What value does the DoD require for the organization-defined parameter in NIST 800-171 R3 03.05.01? R3 leaves the value to the organization. For the DIB, the DoD set it in the 10 April 2025 memorandum under ODP identifier 03.05.01.b: roles, authenticators, or credentials change (including modification of user privilege); when security categories of systems change; when the execution of privileged functions occurs; and after a session termination.
How many assessment objectives does NIST 800-171 R3 03.05.01 have? NIST 800-171A R3 breaks 03.05.01 into five (5) assessment objectives: one (1) Organization-Defined Parameters (ODPs) and four (4) determination statements. An assessor works through each one separately, so each needs its own evidence.
Which NIST 800-53 R5 controls does NIST 800-171 R3 03.05.01 come from? IA-02, IA-11.
Where does NIST 800-171 R3 03.05.01 sit in the NIST 800-171 R3 Kill Chain? Phase 13, Identity & Access Management (IAM). The Kill Chain is a phased model for sequencing R3 implementation, and it assigns this requirement to that phase.
03.05.01 User Identification, Authentication, and Re-Authentication uniquely identifies and authenticates users, ties processes to those users, and re-authenticates under defined circumstances. It maps from R2 3.5.1 and 3.5.2 with identification and authentication transitioning directly, while re-authentication and its parameter are new work. The recurring problem is authenticating once and never again, and letting shared accounts erode unique identity. Confirm unique identity, define the re-authentication circumstances (for DoD, the specified set), and enforce them.
Authoritative sources:
Authoritative sources:
This guide reproduces U.S. Government text from NIST 800-171 R3 and NIST 800-171A R3 and references the DoD ODP memorandum of 10 April 2025. It is educational, not legal or assessment advice. Last reviewed: 2026-09-22.
