Alternate Work Site extends physical protection to the places where people work outside the primary facility, most commonly home offices. It is part of the Physical Protection (03.10) family and has become far more consequential as remote and hybrid work have grown. Alternate Work Site (03.10.06) has two (2) parts: determine which alternate work sites employees are allowed to use, and employ a defined set of security requirements at those sites. Per the NIST discussion, alternate work sites include private residences or other designated facilities, they can provide readily available locations during contingency operations, and organizations can define different security requirements for different sites or types of sites depending on the work performed.
A common difficulty with this requirement is letting employees handle Controlled Unclassified Information (CUI) from home with no defined expectations. Remote work is convenient, but a home office is not automatically a controlled area. R3 expects you to decide which alternate sites are allowed and to define and apply security requirements there. For Department of Defense (DoD) contractors, those requirements are specified in terms of adequate, comparable security.
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 03.10.06 Alternate Work Site. Only the formatting has been adjusted for readability. This requirement has two (2) lettered parts:
The source control is PE-17 from NIST 800-53. The bracketed assignment in part b is the Organization-Defined Parameter (ODP): the security requirements for alternate work sites. Per the NIST discussion, assessing the effectiveness of the requirements and providing a means to communicate incidents at alternate work sites supports contingency planning. You can read the requirement directly at NIST 800-171 R3, 03.10.06 (p. 51).
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 03.10.06 into three (3) assessment objectives: one (1) Organization-Defined Parameter (ODP) and two (2) determination statements. These AOs are:
The determination statements are determining the allowed sites and employing the security requirements there. 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, the security requirements (ODP[01]) are adequate security, comparable to the organizational security requirements at the primary work site where practical, documented in policy, and covered by training. The full guidance on assessment methods and objects, is in NIST 800-171A R3, 03.10.06 (p. 66).
Examine: physical protection policy and procedures; procedures for alternate work sites for personnel; list of security requirements for alternate work sites; assessments of security requirements at alternate work sites; system security plan.
Interview: personnel approving the use of alternate work sites; personnel using alternate work sites; personnel assessing security requirements at alternate work sites; personnel with information security responsibilities.
Test: processes for security at alternate work sites; mechanisms for supporting alternate work sites; security requirements employed at alternate work sites; means of communication between personnel at alternate work sites and security personnel.
03.10.06 maps from NIST 800-171 R2 requirement 3.10.6 (enforce safeguarding measures for CUI at alternate work sites):
Mapped against the three (3) AOs, two (2) are direct (minimal effort) and one (1) has no clear mapping (significant effort), with none indirect and none net new. Defining and enforcing the security requirements carry forward, but determining which alternate work sites are allowed is the objective that does not trace cleanly to a R2 objective. Decide and document the permitted sites rather than allowing work from anywhere by default.
Source Control in NIST 800-53 R5:
Secure Controls Framework (SCF) Crosswalk
Organizations running a single control set across multiple frameworks can satisfy 03.10.06 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 defining allowed sites and comparable security, 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 03.10.06 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 03.10.06 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 03.10.06 recording the ODP values you adopted.
With two (2) AOs mapping directly and one with no clear mapping, 03.10.06 is a light lift with one decision to formalize. A realistic sequence:
What value does the DoD require for the organization-defined parameter in NIST 800-171 R3 03.10.06? R3 leaves the value to the organization. For the DIB, the DoD set it in the 10 April 2025 memorandum under ODP identifier 03.10.06.b: adequate security, comparable to organizational security requirements at the primary work site where practical, documented in policy, and covered by training.
How many assessment objectives does NIST 800-171 R3 03.10.06 have? NIST 800-171A R3 breaks 03.10.06 into three (3) assessment objectives: one (1) Organization-Defined Parameters (ODPs) and two (2) determination statements. An assessor works through each one separately, so each needs its own evidence.
Which NIST 800-53 R5 control does NIST 800-171 R3 03.10.06 come from? PE-17.
Where does NIST 800-171 R3 03.10.06 sit in the NIST 800-171 R3 Kill Chain? Phase 20, Physical Security. The Kill Chain is a phased model for sequencing R3 implementation, and it assigns this requirement to that phase.
03.10.06 Alternate Work Site determines which alternate sites employees may use and employs defined security requirements there. It maps from R2 3.10.6 with defining and enforcing security requirements transitioning directly, while determining the allowed sites has no clear R2 mapping. The recurring problem is letting people handle CUI from home with no defined expectations. Decide the permitted sites, define comparable security requirements (for DoD, documented and trained), 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.
