Multi-Factor Authentication is one of the shortest requirements in NIST 800-171 R3 and one of the most consequential. It requires multi-factor authentication (MFA) for access to privileged and non-privileged accounts. MFA requires two or more different authentication factors: something you know, such as a personal identification number, something you have, such as a hardware authenticator or cryptographic key, or something you are, such as a biometric. Multi-Factor Authentication (03.05.03) sits alongside User Identification, Authentication, and Re-Authentication (03.05.01), which establishes identity, by strengthening how that identity is proven.
A common difficulty with this requirement is assuming their R2 MFA deployment already covers it. It probably does not. R2 required MFA for local and network access to privileged accounts and for network access to non-privileged accounts, which left a gap: local access to non-privileged accounts. R3 removes the local and network distinction entirely and requires MFA for access to both privileged and non-privileged accounts. That means the workstation login for an ordinary user, which many R2 programs left as a password, now needs MFA.
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 03.05.03 Multi-Factor Authentication. Only the formatting has been adjusted for readability. This is a single statement with no lettered parts:
The source controls are IA-02(01) and IA-02(02) from NIST 800-53. There are no Organization-Defined Parameters (ODPs). Per the NIST discussion, this requirement applies to user accounts, MFA requires two or more different factors, and organizations may also employ authentication mechanisms at the application level in addition to the system level for increased protection. You can read the requirement directly at NIST 800-171 R3, 03.05.03 (p. 34).
None (0). Requirement 03.05.03 contains no bracketed assignment, so there is no organization-defined value to select and nothing for the DoD to specify. The requirement applies as written.
Your System Security Plan (SSP) narrative for 03.05.03 therefore records how the requirement is implemented rather than a parameter you chose.
NIST 800-171A R3 breaks 03.05.03 into two (2) determination statements, and it has no Organization-Defined Parameters (ODPs). These AOs are:
The two (2) objectives are MFA for privileged accounts and MFA for non-privileged accounts, and neither is qualified by local or network access, so both cover all access. An assessor checks both. The full guidance on assessment methods and objects, is in NIST 800-171A R3, 03.05.03 (p. 43).
Examine: identification and authentication policy and procedures; system design documentation; list of system accounts; system configuration settings; system audit records; system security plan.
Interview: personnel with system operations responsibilities; personnel with account management responsibilities; personnel with information security responsibilities; system developers; system administrators.
Test: mechanisms for supporting or implementing a multi-factor authentication capability.
03.05.03 maps from NIST 800-171 R2 requirement 3.5.3 (use multifactor authentication for local and network access to privileged accounts and for network access to non-privileged accounts):
Mapped against the two (2) AOs, both (2) are direct (minimal effort), with no net-new AOs and none with no mapping. The direct mapping is misleading, though, because the scope broadened. R2 3.5.3 required MFA for local and network access to privileged accounts but only network access to non-privileged accounts. R3 drops the local and network qualifiers and requires MFA for all access to both account types. The objectives map directly, but satisfying them may require extending MFA to local, non-privileged logins that R2 did not cover.
Source Controls in NIST 800-53 R5:
Secure Controls Framework (SCF) Crosswalk
Organizations running a single control set across multiple frameworks can satisfy 03.05.03 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 the broadened scope and factor quality, 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 03.05.03 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 03.05.03 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 03.05.03.
With both AOs mapping directly, 03.05.03 looks simple, but extending MFA to all access can be a real project. A realistic sequence:
How many assessment objectives does NIST 800-171 R3 03.05.03 have? NIST 800-171A R3 breaks 03.05.03 into two (2) assessment objectives. An assessor works through each one separately, so each needs its own evidence.
Which NIST 800-53 R5 controls does NIST 800-171 R3 03.05.03 come from? IA-02(01), IA-02(02).
How many Organization-Defined Parameters (ODPs) does NIST 800-171 R3 03.05.03 have? None (0). The requirement contains no bracketed assignment, so there is no organization-defined value and nothing for the DoD to specify.
Where does NIST 800-171 R3 03.05.03 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.
03.05.03 Multi-Factor Authentication requires MFA for access to privileged and non-privileged accounts. It maps directly from R2 3.5.3, but R3 removes the local and network qualifiers, so MFA now applies to all access, including the local, non-privileged logins R2 left out. The recurring problem is assuming a R2 MFA rollout is enough. Extend MFA to all access to both account types, use factors from different categories, and keep the configuration as evidence.
Authoritative sources:
Authoritative sources:
This guide reproduces U.S. Government text from NIST 800-171 R3 and NIST 800-171A R3. It is educational, not legal or assessment advice. Last reviewed: 2026-09-22.
