Understanding NIST 800-171A

If you’re trying to understand what federal cybersecurity requirements apply to your organization, you’re likely to find yourself in a blizzard of codes and acronyms.

Two you may have encountered are NIST 800-171 and NIST 800-171A. What are they? How do they differ from each other? And what do you, as a DoD contractor, need to know about them to stay in compliance with the law? This blog answers all these questions and more.

What Is NIST 800-171?

NIST 800-171 is a set of cybersecurity guidelines issued by the National Institute of Standards and Technology (NIST) aimed at protecting Controlled Unclassified Information (CUI) in non-federal systems and organizations. It provides 110 security requirements across 14 control families that organizations must implement to safeguard CUI from unauthorized access, disclosure, or theft. NIST 800-171 ensures that companies handling CUI are securing their systems to the highest standards​​.

For companies working with the U.S. government, especially the Department of Defense (DoD), compliance with NIST 800-171 is often mandatory. The Defense Federal Acquisition Regulation Supplement (DFARS) Clause 252.204-7012 requires defense contractors to implement NIST 800-171 controls to safeguard CUI and report any cybersecurity incidents.

In addition, the requirements in NIST 800-171 form the basis for the Cybersecurity Maturity Model Certification (CMMC). Contractors seeking CMMC Level 2 certification, for instance, must fully implement all 110 security requirements from NIST 800-171. This makes it a key component in preparing for CMMC certification, which will soon be necessary for nearly all defense contractors.

What Is NIST 800-171A?

NIST 800-171A is a supplemental document to NIST Special Publication 800-171. It provides guidelines for assessing the implementation of the security controls specified in that publication. NIST 800-171A explains in detail how organizations should measure their compliance with each control under NIST 800-171, facilitating audits, self-assessments, and preparation for official assessments like CMMC certifications​​​.

The Difference Between NIST 800-171 and NIST 800-171A

The difference between NIST 800-171 and NIST 800-171A lies in their purpose: 

• NIST SP 800-171 is the core framework that outlines security requirements for protecting CUI in non-federal systems and organizations. It provides specific security practices and guidelines that organizations must follow to safeguard this information, focusing on things like access control, incident response, and system security.
• NIST SP 800-171A is a companion document that establishes specific assessment objectives and methods for testing the implementation of each security requirement in NIST 800-171. Essentially, it’s a practical guide for evaluating compliance with NIST 800-171 requirements.

In short:

• NIST 800-171 tells you what to do to protect CUI.

• NIST 800-171A tells you how to assess if you're doing it correctly.

How NIST 800-171A relates to CMMC

CMMC Level 2 (and some parts of Level 3) is closely aligned with the security requirements in NIST 800-171. Defense contractors working with CUI must comply with these controls to meet CMMC Level 2 certification. NIST 800-171A is therefore foundational to CMMC because it provides the assessment methodology for evaluating compliance with those security controls.

Think of it like this: If NIST 800-171 is the textbook, NIST 800-171A is the study guide, and CMMC is the test.

Organizations seeking CMMC certification can use NIST 800-171A to conduct self-assessments and prepare for official audits. It helps ensure that the required controls are not only in place but also functioning as intended, which is a core requirement for passing a CMMC assessment.

Who Needs to Be NIST Compliant?

If your business is part of the Defense Industrial Base (DIB) and handles CUI or FCI (Federal Contract Information), you’ll need to be CMMC certified. NIST 800-171A sets three assessment levels: Basic, Intermediate, and Advanced (or, as they’re referred to in the CMMC process, Level 1, Level 2, and Level 3). The level of security your business needs depends on the sensitivity of the information you're working with and the specific requirements of your contract(s).

Work with ISI to Master Your NIST 800-171 Compliance Needs

At ISI, we understand the challenges of cybersecurity compliance, and we’re here to support you every step of the way. We believe that continuous cybersecurity maturity is more than a compliance necessity: it can help you achieve true operational excellence and allow you to shine with your government customers.

With over 300 years of combined industrial security experience and three Registered Practitioners on our team, our team of experts offers comprehensive support to organizations in all stages of the CMMC assessment readiness process. Through cost effective guidance, expert vendor management, streamlined assessment preparation, and reliable IT and cybersecurity support, we’ll push you over the finish line.

Contact ISI today to learn more about how we can assist you in achieving and maintaining your compliance goals.

FAQs about NIST 800-171A 

What Are NIST Controls and How Many Controls Are There in NIST 800-171?

NIST “controls” are specific security requirements or practices designed to protect information systems and data from cybersecurity threats. There are 110 controls in NIST 800-171a rev2 that are divided into 14 families, such as access control, incident response, and system protection. Compliance with all 110 of these controls is crucial for defense contractors seeking Level 2 CMMC compliance.

How Long Does It Take to Get NIST Certification?

Technically, there is no official NIST certification for NIST 800-171; that’s what CMMC is for. For companies aiming to meet CMMC Level 2 requirements, which align with NIST 800-171, the process may take anywhere from a few months to over a year, based on the organization's initial readiness, the scope of necessary improvements, and the time it takes to find a third-party assessor.

What’s the Difference Between NIST 800-171 and NIST 800-172?

NIST 800-172 is an enhanced supplement to 800-171, offering additional advanced security controls to protect high-value assets and critical programs from more sophisticated cyber threats, such as nation-state actors. While 800-171 is widely applicable, 800-172 is used in CMMC Level 3 and other environments requiring higher levels of protection due to the sensitivity of the information.

What’s the Difference Between NIST 800-171 and ISO 27001 

NIST 800-171 is a U.S.-specific standard for protecting CUI in organizations working with the U.S. government. ISO 27001 is an international standard for establishing, implementing, and maintaining an Information Security Management System (ISMS). It’s broader and applies to any organization worldwide, offering a framework for managing information security risks across organizations.

While both aim to protect sensitive data, NIST 800-171 is more prescriptive with its controls and limited in its application, whereas ISO 27001 is a global standard focused on risk management and continuous improvement across industries.

Does NIST 800-171 Require FedRAMP?

NIST 800-171 focuses on protecting CUI in non-federal systems, while FedRAMP (the Federal Risk and Authorization Management Program) applies to cloud service providers offering services to federal agencies.

However, if a private contractor uses a cloud service to store or process CUI, the cloud provider may need to be FedRAMP-authorized (or FredRAMP Moderate Baseline equivalent) to comply with NIST 800-171 regulations, since FedRAMP ensures that cloud services meet federal security standards.