Cybersecurity Maturity Model Certification (CMMC) and NIST 800-171 are comprehensive security frameworks designed to safeguard government data and improve the security posture of organizations handling that data.
While these frameworks are closely related, they’re not interchangeable. Understanding the differences between them is particularly important for organizations seeking to work with federal agencies, specifically the Department of Defense (DoD).
To clarify the relationship between CMMC and NIST 800-171, this guide will provide quick overviews of both frameworks, as well as their key similarities and differences.
What is CMMC?
CMMC is a federal security program that aims to safeguard the DoD and its supply chain through a series of prescriptive practices. The program aims to protect two types of data:
- Federal Contract Information (FCI), which refers to information related to government contracts
- Controlled Unclassified Information (CUI), which includes sensitive data related to national security
The initial version (CMMC 1.0) was released in 2020 and underwent many changes to ensure clarity and enable more streamlined implementation.
With the release of the CMMC Final Rule in October 2024, CMMC 2.0 came into effect. The DoD is already enforcing the regulation’s many practices, and the implementation will occur in four phases:
- Phase 1 (mid-2025): In-scope organizations must complete self-assessments for Level 1 and permitted Level 2 solicitations
- Phase 2 (mid-2026): Organizations are obligated to obtain certificates for the applicable Level 2 contracts
- Phase 3 (mid-2027): The DoD will start including the specific requirements for Level 3 certification in select contracts
- Phase 4 (mid-2028): All solicitations and contracts will include the appropriate CMMC certification level as a requirement for contract award
{{cta_withimage27="/cta-blocks"}} | CMMC compliance checklist
What is NIST 800-171?
NIST 800-171 is a robust publication outlining the security practices for safeguarding CUI. CMMC aims to protect the same data alongside FCI, which is why these two frameworks are so closely related.
Implementation of NIST 800-171 started sooner than CMMC—defense contractors began self-assessing against its practices in 2017 as a requirement for pursuing government contracts.
The latest version of NIST 800-171 is Rev. 3, though Rev. 2 is more relevant in the CMMC context because the two frameworks closely align in their security practices.
The relationship between CMMC and NIST 800-171
CMMC and NIST 800-171 aren’t mutually exclusive—they’re strongly connected because CMMC is largely based on the NIST 800-171 practices. It directly draws from NIST 800-171 and its 14 control families:
- Access Control (AC)
- Awareness and Training (AT)
- Audit & Accountability (AU)
- Configuration Management (CM)
- Identification & Authentication (IA)
- Incident Response (IR)
- Maintenance (MA)
- Media Protection (MP)
- Personnel Security (PS)
- Physical Protection (PE)
- Risk Assessment (RA)
- Security Assessment (CA)
- System and Communications Protection (SC)
- System and Information Integrity (SI)
Meeting the requirements in these areas is key to achieving CMMC compliance. While the specific number of practices required can vary depending on the certification level (more on that later), these 14 control families form the foundation of the framework.
Because of this close relationship, organizations that have already implemented NIST 800-171 should be able to achieve CMMC compliance without much effort. Still, this doesn’t make them fully CMMC-compliant due to the notable differences between these frameworks.
{{cta_withimage22="/cta-blocks"}} | The audit ready checklist
5 differences between CMMC and NIST 800-171
CMMC and NIST 800-171 differ in five key areas:
- Legal weight
- Scope
- Applicability
- Structure
- Attestation
Below, we’ll explore each difference in more detail.
1. Legal weight
NIST 800-171 isn’t directly enforced by regulatory or government bodies. Instead, its requirements are only mandatory when specified in contracts, such as those with the DoD. The framework encompasses a set of security best practices that an organization may or may not need to implement, depending on its security posture and goals.
In contrast, CMMC is directly enforced by the DoD and is mandatory for all organizations that wish to pursue DoD contracts. Depending on an organization’s current relationship with the Department and specific violations, CMMC non-compliance can result in:
- Loss of existing contract
- Missed business opportunities
- Legal consequences (in case of severe non-compliance)
2. Scope
NIST 800-171 only focuses on the protection of CUI. Examples of information that falls under its scope include:
- Operational and tactical data
- Sensitive procurement and acquisition details
- Personally identifiable information (PII)
- Health data
CMMC has a broader scope—it includes CUI, but also focuses on FCI. This is particularly true for Level 1, which is aimed at organizations that handle FCI but not CUI.
The framework also goes beyond NIST 800-171 when it comes to CUI protection. Specifically, Level 3 includes additional practices from NIST SP 800-172, such as:
- Advanced threat awareness
- Cyber incident response teams
- Threat-informed risk assessments
- Penetration testing
3. Applicability
CMMC applies specifically to organizations that wish to work with the DoD. Adherence doesn’t depend on an organization’s size and industry—all current and future contractors must achieve compliance with the level applicable to them.
The only exception is the providers of commercial off-the-shelf (COTS) items, who don’t need certification to work with the DoD.
Because it’s the basis of CMMC practices, NIST 800-171 applies to the same organizations. Still, any organization that wants to work with the federal government outside of the DoD can implement NIST 800-171. CMMC, on the other hand, is specifically required for DoD contractors and their subcontractors.
4. Structure
NIST 800-171 contains a specific set of 110 best practices split into 14 control families. It’s structured as a guide with useful recommendations and security best practices for all organizations that process, store, or transfer CUI.
Given that CMMC is based on NIST 800-171, it leverages all of its controls (specifically in Level 2). Besides Level 2, CMMC has two additional levels with specific requirements. The table below outlines the number of requirements for each CMMC level:
Due to this tiered system, CMMC offers a more structured approach to compliance based on the sensitivity of the data that DoD contractors or subcontractors handle.
5. Attestation
NIST 800-171 compliance typically requires a self-assessment unless otherwise specified in the vendor contract. Organizations must review their security controls, policies, and procedures against the framework’s requirements and collect evidence of full compliance that can be demonstrated to the relevant stakeholders and authorities.
CMMC has a more detailed attestation process, with three types of assessments based on the certification level:
- Self-assessment: Required for Level 1 and some Level 2 certifications; covers basic cybersecurity hygiene
- CMMC Third Party Assessor Organization (C3PAO) assessment: Required for most Level 2 certifications; represents intermediate cybersecurity hygiene
- Government-led assessment: Required for all Level 3 certifications; represents good cybersecurity hygiene
Much like NIST 800-171, CMMC requires comprehensive documentation and evidence collection. Third-party audits involved in some CMMC certification levels make these processes particularly important because inefficient procedures can significantly extend the certification timeline.
As NIST 800-171 doesn’t offer different tiers or make a distinction in the sensitivity of data a company handles, organizations might find it challenging to determine which level of CMMC compliance is right for them based on its practices alone. This is why understanding the differences between FCI and CUI could mean a world of difference in the time it could take to become CMMC-compliant.
A reassuring aspect is that the DoD will specify which level of compliance is required in its contracts and solicitations. If you’re working as a subcontractor to a government contractor, you’ll need to match the level of compliance that the DoD requires of them.
{{cta_withimage27="/cta-blocks"}} | CMMC compliance checklist
Should you adopt NIST 800-171 or the CMMC?
Your chosen security framework mainly depends on your business goals. If you plan on working with the DoD, you’ll need CMMC. While you can still implement NIST 800-171, doing so won’t be enough to meet all of the regulation’s requirements.
“
We often hear organizations say, ‘As long as I am NIST 800-171 compliant, I’m compliant with CMMC,’ and that’s not right. While CMMC is based on NIST 800-171 practices, it goes a step further in requiring companies to define the level of data they interact with (FCI vs. CUI), the sensitivity of that data, and applying additional controls beyond NIST 800-171 to ensure protection of that data.”
While NIST 800-171 doesn’t ensure CMMC compliance, it considerably streamlines it due to the notable overlap in practices. Still, adopting either framework requires a methodical approach because they both come with comprehensive security requirements.
To speed up compliance, you need to streamline your workflows and remove laborious processes. Adopting a compliance automation solution is an excellent way to make this happen.
Implement CMMC and NIST 800-171 efficiently with Vanta
Vanta is a trust management platform that supports organizations in CMMC compliance efforts through structured guidance across controls, policies, and documents, and a variety of tools designed to streamline the certification process.
Its robust CMMC product is equipped with features that automate up to 50 percent of CMMC workflows, such as:
- Out-of-the-box support for all certification levels
- Automated gap assessments
- Pre-mapped security controls aligned to NIST SP 800-171 and NIST SP 800-172
- Automated evidence collection supported by 375+ integrations
- Centralized tracking and monitoring of CMMC practices
Vanta supports over 35 additional frameworks and standards (including NIST 800-171), and it automatically cross-references your existing controls with different standards to help you avoid duplicative workflows and manage compliance with several frameworks within a unified solution.
Schedule a custom demo of Vanta’s CMMC product to see how it saves organizations time and optimizes compliance processes.
{{cta_simple33="/cta-blocks"}} | CMMC product page
A note from Vanta: Vanta is not a law firm, and this article does not constitute or contain legal advice or create an attorney-client relationship. When determining your obligations and compliance with respect to relevant laws and regulations, you should consult a licensed attorney.
CMMC vs. NIST 800-171: Relationship and differences
Looking to automate up to 50% of the work for CMMC?
Cybersecurity Maturity Model Certification (CMMC) and NIST 800-171 are comprehensive security frameworks designed to safeguard government data and improve the security posture of organizations handling that data.
While these frameworks are closely related, they’re not interchangeable. Understanding the differences between them is particularly important for organizations seeking to work with federal agencies, specifically the Department of Defense (DoD).
To clarify the relationship between CMMC and NIST 800-171, this guide will provide quick overviews of both frameworks, as well as their key similarities and differences.
What is CMMC?
CMMC is a federal security program that aims to safeguard the DoD and its supply chain through a series of prescriptive practices. The program aims to protect two types of data:
- Federal Contract Information (FCI), which refers to information related to government contracts
- Controlled Unclassified Information (CUI), which includes sensitive data related to national security
The initial version (CMMC 1.0) was released in 2020 and underwent many changes to ensure clarity and enable more streamlined implementation.
With the release of the CMMC Final Rule in October 2024, CMMC 2.0 came into effect. The DoD is already enforcing the regulation’s many practices, and the implementation will occur in four phases:
- Phase 1 (mid-2025): In-scope organizations must complete self-assessments for Level 1 and permitted Level 2 solicitations
- Phase 2 (mid-2026): Organizations are obligated to obtain certificates for the applicable Level 2 contracts
- Phase 3 (mid-2027): The DoD will start including the specific requirements for Level 3 certification in select contracts
- Phase 4 (mid-2028): All solicitations and contracts will include the appropriate CMMC certification level as a requirement for contract award
{{cta_withimage27="/cta-blocks"}} | CMMC compliance checklist
What is NIST 800-171?
NIST 800-171 is a robust publication outlining the security practices for safeguarding CUI. CMMC aims to protect the same data alongside FCI, which is why these two frameworks are so closely related.
Implementation of NIST 800-171 started sooner than CMMC—defense contractors began self-assessing against its practices in 2017 as a requirement for pursuing government contracts.
The latest version of NIST 800-171 is Rev. 3, though Rev. 2 is more relevant in the CMMC context because the two frameworks closely align in their security practices.
The relationship between CMMC and NIST 800-171
CMMC and NIST 800-171 aren’t mutually exclusive—they’re strongly connected because CMMC is largely based on the NIST 800-171 practices. It directly draws from NIST 800-171 and its 14 control families:
- Access Control (AC)
- Awareness and Training (AT)
- Audit & Accountability (AU)
- Configuration Management (CM)
- Identification & Authentication (IA)
- Incident Response (IR)
- Maintenance (MA)
- Media Protection (MP)
- Personnel Security (PS)
- Physical Protection (PE)
- Risk Assessment (RA)
- Security Assessment (CA)
- System and Communications Protection (SC)
- System and Information Integrity (SI)
Meeting the requirements in these areas is key to achieving CMMC compliance. While the specific number of practices required can vary depending on the certification level (more on that later), these 14 control families form the foundation of the framework.
Because of this close relationship, organizations that have already implemented NIST 800-171 should be able to achieve CMMC compliance without much effort. Still, this doesn’t make them fully CMMC-compliant due to the notable differences between these frameworks.
{{cta_withimage22="/cta-blocks"}} | The audit ready checklist
5 differences between CMMC and NIST 800-171
CMMC and NIST 800-171 differ in five key areas:
- Legal weight
- Scope
- Applicability
- Structure
- Attestation
Below, we’ll explore each difference in more detail.
1. Legal weight
NIST 800-171 isn’t directly enforced by regulatory or government bodies. Instead, its requirements are only mandatory when specified in contracts, such as those with the DoD. The framework encompasses a set of security best practices that an organization may or may not need to implement, depending on its security posture and goals.
In contrast, CMMC is directly enforced by the DoD and is mandatory for all organizations that wish to pursue DoD contracts. Depending on an organization’s current relationship with the Department and specific violations, CMMC non-compliance can result in:
- Loss of existing contract
- Missed business opportunities
- Legal consequences (in case of severe non-compliance)
2. Scope
NIST 800-171 only focuses on the protection of CUI. Examples of information that falls under its scope include:
- Operational and tactical data
- Sensitive procurement and acquisition details
- Personally identifiable information (PII)
- Health data
CMMC has a broader scope—it includes CUI, but also focuses on FCI. This is particularly true for Level 1, which is aimed at organizations that handle FCI but not CUI.
The framework also goes beyond NIST 800-171 when it comes to CUI protection. Specifically, Level 3 includes additional practices from NIST SP 800-172, such as:
- Advanced threat awareness
- Cyber incident response teams
- Threat-informed risk assessments
- Penetration testing
3. Applicability
CMMC applies specifically to organizations that wish to work with the DoD. Adherence doesn’t depend on an organization’s size and industry—all current and future contractors must achieve compliance with the level applicable to them.
The only exception is the providers of commercial off-the-shelf (COTS) items, who don’t need certification to work with the DoD.
Because it’s the basis of CMMC practices, NIST 800-171 applies to the same organizations. Still, any organization that wants to work with the federal government outside of the DoD can implement NIST 800-171. CMMC, on the other hand, is specifically required for DoD contractors and their subcontractors.
4. Structure
NIST 800-171 contains a specific set of 110 best practices split into 14 control families. It’s structured as a guide with useful recommendations and security best practices for all organizations that process, store, or transfer CUI.
Given that CMMC is based on NIST 800-171, it leverages all of its controls (specifically in Level 2). Besides Level 2, CMMC has two additional levels with specific requirements. The table below outlines the number of requirements for each CMMC level:
Due to this tiered system, CMMC offers a more structured approach to compliance based on the sensitivity of the data that DoD contractors or subcontractors handle.
5. Attestation
NIST 800-171 compliance typically requires a self-assessment unless otherwise specified in the vendor contract. Organizations must review their security controls, policies, and procedures against the framework’s requirements and collect evidence of full compliance that can be demonstrated to the relevant stakeholders and authorities.
CMMC has a more detailed attestation process, with three types of assessments based on the certification level:
- Self-assessment: Required for Level 1 and some Level 2 certifications; covers basic cybersecurity hygiene
- CMMC Third Party Assessor Organization (C3PAO) assessment: Required for most Level 2 certifications; represents intermediate cybersecurity hygiene
- Government-led assessment: Required for all Level 3 certifications; represents good cybersecurity hygiene
Much like NIST 800-171, CMMC requires comprehensive documentation and evidence collection. Third-party audits involved in some CMMC certification levels make these processes particularly important because inefficient procedures can significantly extend the certification timeline.
As NIST 800-171 doesn’t offer different tiers or make a distinction in the sensitivity of data a company handles, organizations might find it challenging to determine which level of CMMC compliance is right for them based on its practices alone. This is why understanding the differences between FCI and CUI could mean a world of difference in the time it could take to become CMMC-compliant.
A reassuring aspect is that the DoD will specify which level of compliance is required in its contracts and solicitations. If you’re working as a subcontractor to a government contractor, you’ll need to match the level of compliance that the DoD requires of them.
{{cta_withimage27="/cta-blocks"}} | CMMC compliance checklist
Should you adopt NIST 800-171 or the CMMC?
Your chosen security framework mainly depends on your business goals. If you plan on working with the DoD, you’ll need CMMC. While you can still implement NIST 800-171, doing so won’t be enough to meet all of the regulation’s requirements.
“
We often hear organizations say, ‘As long as I am NIST 800-171 compliant, I’m compliant with CMMC,’ and that’s not right. While CMMC is based on NIST 800-171 practices, it goes a step further in requiring companies to define the level of data they interact with (FCI vs. CUI), the sensitivity of that data, and applying additional controls beyond NIST 800-171 to ensure protection of that data.”
While NIST 800-171 doesn’t ensure CMMC compliance, it considerably streamlines it due to the notable overlap in practices. Still, adopting either framework requires a methodical approach because they both come with comprehensive security requirements.
To speed up compliance, you need to streamline your workflows and remove laborious processes. Adopting a compliance automation solution is an excellent way to make this happen.
Implement CMMC and NIST 800-171 efficiently with Vanta
Vanta is a trust management platform that supports organizations in CMMC compliance efforts through structured guidance across controls, policies, and documents, and a variety of tools designed to streamline the certification process.
Its robust CMMC product is equipped with features that automate up to 50 percent of CMMC workflows, such as:
- Out-of-the-box support for all certification levels
- Automated gap assessments
- Pre-mapped security controls aligned to NIST SP 800-171 and NIST SP 800-172
- Automated evidence collection supported by 375+ integrations
- Centralized tracking and monitoring of CMMC practices
Vanta supports over 35 additional frameworks and standards (including NIST 800-171), and it automatically cross-references your existing controls with different standards to help you avoid duplicative workflows and manage compliance with several frameworks within a unified solution.
Schedule a custom demo of Vanta’s CMMC product to see how it saves organizations time and optimizes compliance processes.
{{cta_simple33="/cta-blocks"}} | CMMC product page
A note from Vanta: Vanta is not a law firm, and this article does not constitute or contain legal advice or create an attorney-client relationship. When determining your obligations and compliance with respect to relevant laws and regulations, you should consult a licensed attorney.
Explore more CMMC articles
Introduction to CMMC
CMMC requirements
CMMC certification process
CMMC levels
Get started with CMMC
Start your CMMC journey with these related resources.
What you need to know about CMMC—from our Director of Government Strategy & Affairs Morgan Kaplan
Vanta’s director of US government strategy and affairs shares how current and future contractors for the DoD can get CMMC certified.
CMMC Checklist
This checklist will guide you through the steps to take to get CMMC certified and how to successfully implement and maintain the certification.
The ultimate guide to NIST 800-171
Jumpstart your NIST 800-171 compliance with Vanta's complete guide to this legally required security standard.
.png)
.png)
.png)