The short answer: CMMC builds on NIST SP 800-171, but they’re not interchangeable. Let’s break down the difference, how they relate, and what your organization needs to do to stay compliant and competitive.
What Is NIST SP 800-171?
Published in 2015, NIST SP 800-171 is a set of cybersecurity requirements developed by the National Institute of Standards and Technology (NIST). It outlines 110 security requirements designed to protect Controlled Unclassified Information (CUI) in non-federal systems. If your company handles CUI as part of a DoD contract, you’re already expected to implement these controls, even before CMMC.
At its core, NIST SP 800-171 focuses on:
- Access control
- System and communications protection
- Incident response
- Risk assessment
- Audit and accountability
- And more.
Organizations are also expected to self-attest their compliance through documentation like a System Security Plan (SSP) and a Plan of Action and Milestones (POA&M).
What Is CMMC?
CMMC (Cybersecurity Maturity Model Certification) is the DoD’s formal certification program that builds on NIST SP 800-171 requirements. Introduced to address gaps in self-assessment, CMMC 2.0 adds a verification layer to ensure contractors are meeting the security standards they claim to follow.
Here’s how it works:
- CMMC Level 2 aligns directly with all 110 NIST SP 800-171 requirements.
- Instead of self-attesting, select contractors must now pass a third-party assessment by a Certified Third-Party Assessment Organization (C3PAO).
Key Differences at a Glance
| Aspect | NIST SP 800-171 | CMMC 2.0 |
| Purpose | Security standard for protecting CUI | Certification program for DoD contractors |
| Who Requires It | DoD (DFARS 252.204-7012) | DoD (CMMC rulemaking) |
| Level of Enforcement | Self-attestation | 3rd-party certification (for Level 2 contractors) |
| Number of Requirements | 110 | 110 (same as NIST SP 800-171 for Level 2) |
| Documentation Required | SSP, POA&M | SSP, POA&M, plus assessment evidence |
Why DoD Contractors Need to Know the Difference
Being NIST SP 800-171 compliant is not the same as being CMMC Level 2 certified. If you’re preparing to bid on or support DoD contracts, especially those involving CUI, you’ll need to do more than just follow the controls, you’ll need to prove it through CMMC. That’s where many contractors get caught off guard.
Understanding how NIST SP 800-171 and CMMC work together is the first step to maintaining eligibility for DoD opportunities. The next step? Making sure your organization is actually prepared.
Ready to Get CMMC Certified?
Don’t wait for a contract deadline to discover you’re not ready for CMMC. Book your CMMC Readiness Call today or send us an email at CMMCC3PAO@ibsscorp.com to start the path toward certification with a team that knows the process inside and out.
About IBSS
Since 1992, IBSS has provided transformational consulting services to the Federal defense, civilian, and commercial sectors. Our services include cybersecurity and enterprise information technology, environmental science and engineering (including oceans, coasts, climate, weather, and satellite), and professional management services.
Our approach is to serve our employees by investing in their growth and development. As a result, our employees bring greater capabilities and provide an exceptional level of service to our clients. In addition to creating career development opportunities for our employees, IBSS is passionate about giving back to the community. We strive to leave something better behind for the next generation.
We measure our success by the positive impact we have on our employees, clients, partners, and the communities we serve. Our tagline, Powered by Excellence, is a recognition of the employees that make up IBSS and ensures we deliver results with quality, applying industry best practices and certifications. Read more About Us.
Keywords: CMMC, C3PAO, DoD Requirements, NIST SP 800-171
