Key Takeaways
1. CMMC Builds On NIST 800-171 R2 But Enforces It Through Certification: While NIST 800-171 outlines the technical requirements to protect CUI, CMMC adds third-party assessments and maturity expectations to ensure those controls are properly implemented.
2. NIST Compliance Alone Is No Longer Enough for Many DoD Contracts: Under CMMC 2.0, contractors handling CUI must achieve CMMC Level 2 certification—whether self-attested or certified by an Authorized C3PAO.
3. Understanding the Relationship Between NIST and CMMC Is Essential for Contract Eligibility: Confusing the two or assuming they’re interchangeable can result in compliance gaps and missed DoD business opportunities.
If your organization handles Controlled Unclassified Information (CUI) on behalf of the Department of Defense (DoD), understanding the difference between The Cybersecurity Maturity Model Certification (CMMC) and NIST Special Publication 800-171 isn’t just helpful—it’s essential. These two frameworks are closely related, but they serve different purposes in the DoD’s cybersecurity compliance ecosystem. In this post, we’ll break down the relationship between CMMC and NIST, explore where they differ, and explain why understanding both is crucial for securing DoD contracts.
What’s the Difference Between CMMC and NIST?
NIST 800-171 was developed by the National Institute of Standards and Technology (NIST) to provide guidelines for protecting CUI in non-federal systems. It outlines 110 security requirements across 14 control families, including access control, incident response, and system integrity.
Key features of NIST 800-171:
- Designed for federal contractors who store or process CUI
- Requires self-attestation of compliance
- Focuses on safeguarding data confidentiality
- Forms the foundation for many federal cybersecurity requirements
CMMC is a DoD-specific framework that builds upon NIST 800-171 R2. Introduced to enforce accountability and standardize security across the defense industrial base (DIB), CMMC requires third-party assessments for certain contract types.
Key features of CMMC:
- Encompasses multiple maturity levels (Level 1, Level 2, and Level 3 under CMMC 2.0)
- CMMC Level 2 is based directly on the 110 NIST 800-171 R2 controls
- Introduces independent third-party assessments for higher levels
- Adds maturity processes and risk management expectations beyond just technical controls
How CMMC Builds on NIST 800-171 R2
The relationship between NIST 800-171 R2 and CMMC is hierarchical. Think of NIST as the technical baseline and CMMC as the enforcement mechanism.
| Area | NIST 800-171 R2 | CMMC |
| Origin | Developed by NIST | Developed by the DoD |
| Purpose | Provide guidelines to protect CUI | Enforce cybersecurity maturity in the DIB |
| Compliance Method | Self-attestation | Third-party certification (for Level 2 and Level 3) |
| Focus | Security requirements | Security, maturity, and accountability |
| Applicability | All federal contractors with CUI | All entities with DoD contracts that include CMMC requirements 32 CFR / 48 CFR |
| Number of Controls | 110 | Level 2 = 110 (based on NIST 800-171 R2) |
Why the Difference Matters for DoD Contracts
Many defense contractors assume that if they’re already following NIST 800-171, they’re in the clear. But that’s only part of the equation. Under CMMC 2.0, contractors that handle CUI must be formally assessed and certified—self-attestation will no longer be enough for most contracts.
Why it matters:
- CMMC enforces compliance through audits and assessments
- Failing to comply with CMMC can disqualify you from bidding on DoD contracts
- CMMC adds accountability to ensure the 110 NIST controls are actually implemented
The transition from NIST 800-171 self-assessments to CMMC audits represents a shift toward greater cybersecurity accountability across the defense industrial base. Understanding how CMMC and NIST work together—and how they differ—can give your organization a strategic advantage in securing future DoD contracts.
Bottom line? NIST provides the controls. CMMC ensures you’re actually using them.
If you’re ready to begin aligning your organization to the expectations laid out in CMMC and NIST, IS Partners can help. Not only are we an Authorized Certified Third-Party Assessor Organization (C3PAO), certified to conduct CMMC Level 2 cybersecurity assessments, but we also help companies achieve compliance with AI-focused regulations like NIST AI RMF and EU AI Act.
With over 20 years of experience in compliance across industries, we provide a tailored approach to audit preparation and certification—making it easy for companies to identify their existing gaps and create a plan for remediating them. Our experts work seamlessly with your team to avoid disrupting your workflows while still ensuring that you’re fully prepared for your CMMC audit. Interested in learning more? Check out our full suite of CMMC compliance services.
What Should You Do Next?
Perform a NIST 800-171 Gap Assessment: Evaluate your current security posture to identify where you fall short of the 110 required controls.
Engage a CMMC Compliance Expert or Authorized C3PAO: A certified consultant can help you navigate the transition from NIST alignment to full CMMC certification.
Develop a CMMC Readiness Plan: Outline the technical, operational, and documentation steps your organization must take to meet CMMC Level 2 or Level 3 requirements.
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