What You Need to Know About CMMC Level 3
- BAE Networks
- Sep 15
- 3 min read
A Strategic Cybersecurity Investment
Disclaimer: The final CMMC acquisition rule (48 CFR CMMC) has not yet been published; therefore, some of the information below could change.
As cyber threats against national defense systems grow more sophisticated, so must the protections. That’s where CMMC Level 3 comes in; the most advanced and demanding level in the Cybersecurity Maturity Model Certification (“CMMC”) framework.
If your business supports high-priority Department of Defense (“DoD”) programs and works with sensitive Controlled Unclassified Information (“CUI”) critical to national security, Level 3 compliance goes beyond a requirement – it’s a responsibility.
Like our articles for Levels 1 and 2, we’ll take time to explain what CMMC Level 3 is, who it applies to, and how to prepare.
What is CMMC Level 3?
CMMC Level 3 is designed for companies working on DoD contracts that involve the highest priority CUI. This is the information that, if compromised, could pose a significant threat to national security.
Level 3 builds on the requirements of Level 2 by adding 24 enhanced cybersecurity practices from the NIST SP 800-172 standard, plus the expectation of a robust, expert-driven cybersecurity program.
TL;DR: Level 3 is for organizations with the most sensitive DoD information, and it requires enterprise-level security practices.
What are the Requirements?
To achieve Level 3 compliance, your organization must:
Implement 134 practices:
110 practices from NIST SP 800-171 (same as Level 2)
24 additional “advanced” practices from NIST SP 800-172
Demonstrate a managed and optimized cybersecurity program with:
Enterprise-wide planning and oversight
Continuous monitoring and improvement
Advanced threat detection and response capabilities
These tasks aren’t simply just “check-the-box”. They require months of strategic thinking, advanced tooling, and a cybersecurity-first culture.
Who Needs to Comply with Level 3?
Level 3 applies to a select group of defense contractors:
Organizations handling high-value CUI related to critical national security missions.
Prime contractors or subcontractors explicitly required by the DoD to meet Level 3.
Companies supporting programs where nation-state-level adversaries are a realistic threat.
Most small and mid-sized contractors won’t need Level 3, but for those that do, it’s non-negotiable.
Not sure if this applies to you? The DoD will specify Level 3 in contracts where appropriate.
How Should You Prepare?
CMMC Level 3 readiness demands rigorous planning, investment, and expertise. Here’s what your organization should do:
1. Understand the Enhanced Practices
Review the CMMC Level 3 Assessment Guide to understand the full list of 134 practices, especially the 24 advanced ones that go beyond Level 2.
These focus on:
Cyber threat intelligence
Proactive system monitoring
Incident response coordination
Privilege access management
Network segmentation
2. Scope Your Environment
Use the Level 3 Scoping Guide to define:
CUI Assets
Security Protection Assets
Contractor Risk Managed Assets
Specialized Assets
Level 3 assessments apply to any asset with direct or indirect access to CUI, so thorough and accurate scoping is critical.
3. Build, or Mature, Your Cyber Program
Level 3 expects a managed and continuously improved cybersecurity program. You’ll need to:
Maintain current cybersecurity documentation.
Conduct internal audits and reviews.
Implement advanced threat detection and response systems.
Allocate dedicated personnel with appropriate expertise.
4. Conduct a Gap Assessment
Unlike Levels 1 and 2, CMMC Level 3 assessments are conducted by the DoD itself, not by a third party.
These assessments are rigorous and require:
Extensive documentation
Evidence of real-world practice implementation
Participation by senior IT/security leadership
Why It Matters
CMMC Level 3 goes beyond compliance: it’s about national defense and resilience. By meeting these standards, your company demonstrates:
Alignment with the DoD’s highest security priorities.
A proven ability to defend against advanced threats.
Readiness to handle the most sensitive CUI responsibly.
If you're aiming to be a trusted defense partner on mission-critical programs, Level 3 is a clear differentiator.
Final Thoughts
Achieving CMMC Level 3 is a serious commitment, but it proves that your organization supports high-stakes defense initiatives. Level 3 goes beyond protecting your business – it’s about protecting our nation.
If your business falls into CMMC Level 3, BAE Networks can act as a consultant, but is not able to provide a turn-key solution due to the multi-million dollar investment needed on our end.
RESOURCES:
FCI is any information “provided by or generated for the Government under a contract” that is “not intended for public release”, per FAR 52.204-21.
CUI is defined as information that “an entity creates or possesses for…the Government” that requires the entity to “handle using safeguarding or dissemination controls”, per 32 CFR § 2002.4(h).
