Companies that work with government information must have robust cybersecurity. The U.S. government has strict policies to protect sensitive information, especially in defense industries.
Two primary frameworks dictate these initiatives: NIST 800-171 and CMMC compliance. They share a common goal, but they differ from each other. Companies contracting with the Department of Defense (DoD) or government agencies must be familiar with their differences and areas of overlap.
Both also safeguard Controlled Unclassified Information (CUI), but differently. Some firms must comply with both, but others must comply with one.
Knowing how they differ helps organizations meet security needs and avoid compliance issues.
This article breaks down the six primary differences and overlaps.
1. Guidelines vs. Certification
NIST 800-171 establishes guidelines for businesses to comply with to protect Controlled Unclassified Information (CUI). The guidelines dictate specific security controls that entities should adopt, but compliance is generally self-audited. That is, companies must review their security practices, identify areas for improvement, and document their successes.
Also, they must submit a System Security Plan (SSP) and a Plan of Action & Milestones (POA&M) that outline how they intend to remediate weaknesses. They do not automatically receive external certification, but this can be requested by a contracting official or by a government agency. In most cases, firms voluntarily report their status for compliance without having it audited by an outside agency.
Conversely, CMMC compliance is far more rigid in its methodology. Instead of using self-assessments, there is a formal certification process. CMMC was established by the Department of Defense (DoD) and mandates that companies be third-party audited to determine that they meet standards before being qualified for DoD contracts. While NIST 800-171 allows companies to self-certify, CMMC requires third-party verification by a qualified assessor, with added accountability and security.
2. Single Standard vs. Tiered Levels
Conversely, NIST 800-171 sets a single set of requirements for all enterprises that handle CUI. All enterprises, irrespective of size and type of activity, must adhere to the same set of security controls.
Besides, no contract variations by size or risk level exist—companies comply or do not. Compliance is simple but does not account for differing cybersecurity maturity levels across firms.
In contrast, CMMC compliance is tiered with three distinct levels of protection. Level 1 is focused on general cybersecurity protections like password management and access control. Level 2 is quite in sync with NIST 800-171, with additional advanced protection for sensitive information.
Furthermore, Level 3 has stronger protections for companies that deal with highly sensitive DoD information. The tiered nature allows smaller companies to comply with less stringent requirements but necessitates larger defense contractors to implement stronger protections.
3. Self-Reporting vs. Third-Party Validation
The most striking difference is in ensuring compliance. NIST 800-171 allows company self-assessment and self-reporting regarding compliance status. Companies identify areas lacking security, create a Plan of Action & Milestones (POA&M) for remedial actions, and submit their scores to the government if required. There is no requirement for an external audit unless a contracting agency specifically requests it.
CMMC requires a formal third-party assessment. Companies must be audited by a Certified Third-Party Assessor Organization (C3PAO) to verify that their security controls comply with the standards.
However, companies cannot be granted particular DoD contracts if they do not obtain this certification. Unlike NIST 800-171, companies cannot self-certify their compliance; they must prove it with a third-party assessment.
4. Broad Application vs. DoD-Specific
Whereas CMMC is explicitly applied to defense contractors, NIST 800-171 applies to more general firm classes. Any organization with a government agency contract dealing with Controlled Unclassified Information (CUI) is subject to NIST 800-171 standards.
Contractors, subcontractors, and business entities in numerous industries, not just defense-related industries, fall within this category. Compliance is required if a company works with sensitive government information, irrespective of its contracting agency.
Conversely, CMMC is strictly a Department of Defense (DoD) requirement. DoD contract bidders alone would need to be CMMC-certified. However, other business entities contracting with the DoD and government agencies would likely be required by both standards. As CMMC Level 2 is compatible with NIST 800-171, most defense contractors would be needed for both standards.
5. Compliance vs. Maturity
NIST 800-171 is an essential compliance. Companies must implement a set of security controls and document their status. They target specific security requirements, but there is no requirement for continuous improvement. As long as the guidelines are adhered to, the company is compliant.
CMMC is maturity-focused. Instead of compliance with security specifications, companies must show that they integrate cybersecurity as a routine. Companies must demonstrate ongoing improvement, regular monitoring, and an awareness culture. CMMC is designed to be dynamic, keep up with cybersecurity threats, and push companies toward long-term maturity in security and not point-in-time compliance.
6. Stable vs. Evolving Framework
NIST 800-171 has remained stable over the years. Sure, revision updates made the security controls more specific, but the framework didn’t change much. Businesses that know NIST 800-171 can confidently prepare their compliance, knowing that the requirements haven’t changed.
However, CMMC keeps developing. The DoD initially released CMMC 1.0 with five levels but later revised it to CMMC 2.0 with three levels, closer to NIST 800-171. Updates could be made in the future as threats change. Businesses must stay compliant with the latest CMMC requirements.
Key Takeaway
CMMC and NIST 800-171 protect government information but for different reasons. NIST 800-171 is a standard, and CMMC is a certification. One is self-certified, and the other is third-party audited. NIST 800-171 is general, and CMMC is DoD only.
Government agencies’ contracting offices should pay attention to these overlaps and differences. Compliance with changing cybersecurity laws means strong security, contract eligibility and long-term government contracting success.