As the Cybersecurity Maturity Model Certification (CMMC) 2.0 framework continues its rollout, the Department of Defense (DoD) has made one thing clear — cybersecurity isn’t just a compliance checkbox anymore. It’s a national security priority.
While CMMC Level 1 and Level 2 focus on safeguarding Federal Contract Information (FCI) and Controlled Unclassified Information (CUI), CMMC Level 3 (“Expert”) is designed to protect the most sensitive CUI and defend against Advanced Persistent Threats (APTs).
For defense contractors supporting critical missions or high-value programs, achieving Level 3 will be essential for continued eligibility and credibility within the Defense Industrial Base (DIB).
What Is CMMC Level 3?
CMMC Level 3 builds directly on the 110 controls from NIST SP 800-171 required at Level 2, and adds 24 enhanced practices from NIST SP 800-172, creating a total of 134 security requirements.
These enhanced practices go beyond basic protection — they emphasize detection, response, and resilience against sophisticated adversaries, including foreign nation-state cyber actors.
CMMC Level 3 Requirements Overview
Unlike Levels 1 and 2, Level 3 assessments will not be conducted by commercial third parties (C3PAOs). Instead, they will be performed by the Defense Industrial Base Cybersecurity Assessment Center (DIBCAC) under the Defense Contract Management Agency (DCMA).
Who Needs CMMC Level 3?
Level 3 applies to organizations:
Working with high-priority or critical defense programs;
Handling CUI associated with national security systems;
Or supporting weapons systems, intelligence, or command-and-control environments.
Only a small subset of defense contractors (estimated at less than 5% of the DIB) will require Level 3 certification.
Preparing for CMMC Level 3 Compliance
1. Build on a Mature Level 2 Foundation
Level 3 readiness begins with complete and validated Level 2 compliance. Review your System Security Plan (SSP) and Plan of Action & Milestones (POA&M) to ensure all 110 NIST 800-171 controls are met and documented.
2. Implement NIST SP 800-172 Controls
Focus on advanced controls in:
Threat Intelligence Sharing
Anomaly-Based Intrusion Detection
Privileged Account Monitoring
Zero-Trust Architecture Principles
Because these controls emphasize real-time resilience, organizations often integrate Security Information and Event Management (SIEM) tools and Endpoint Detection and Response (EDR) systems.
3. Enhance Insider Threat Programs
The DoD expects Level 3 organizations to have documented insider-threat detection and mitigation programs integrated into security operations.
4. Conduct Red-Team Exercises and Tabletop Simulations
Proactively test detection and response capabilities with red-team/blue-team exercises. Capture lessons learned and update incident playbooks accordingly.
5. Engage Executives and Technical Leads
Level 3 compliance requires top-down commitment. Senior executives must support funding, training, and strategic risk management — not just technical implementation.
The DoD’s Role in Level 3 Oversight
CMMC Level 3 assessments are managed directly by DoD assessors, not by commercial C3PAOs. These assessments will be:
In-depth and on-site (for high-risk environments);
Renewed every three years;
And potentially supplemented by continuous monitoring or spot checks between cycles.
Results will be stored in the Supplier Performance Risk System (SPRS), affecting contract eligibility and renewal opportunities. (sprs.csd.disa.mil)
Strategic Benefits of Achieving Level 3
Competitive Advantage: Eligibility for high-value, classified, or national security contracts.
Enhanced Reputation: Demonstrates superior cybersecurity maturity and trustworthiness.
Stronger Resilience: Reduces breach risk and improves recovery from cyber incidents.
Future-Proofing: Aligns with DoD’s movement toward zero-trust and continuous monitoring mandates.
Final Thoughts
CMMC Level 3 represents the pinnacle of defense contractor cybersecurity maturity. While few organizations will need to reach this level, those that do will play a critical role in securing America’s defense supply chain against sophisticated adversaries.
Preparing early—by integrating NIST SP 800-172 controls, adopting zero-trust principles, and strengthening continuous monitoring—ensures that when Level 3 clauses appear in solicitations, your organization is already positioned for success.
In cybersecurity, waiting is the biggest vulnerability. Start building your Level 3 roadmap now.
References
Department of Defense, CMMC Program Final Rule (32 CFR Part 170). federalregister.gov
DoD Chief Information Officer, CMMC Overview. dodcio.defense.gov
National Institute of Standards and Technology, NIST SP 800-172: Enhanced Security Requirements for Protecting Controlled Unclassified Information. nist.gov
REGISTER FOR OUR WEBINAR ON NOV 6:
How to Meet New CMMC Requirements Webinar 11/6 @ 11 AM EST
Click on the link: Join event
👉 Request your customized cyber vulnerability report today and stay ahead of threats.
👉 Gain insights into your unique cybersecurity vulnerabilities with a custom report.
👉 Train your team to be your first line of defense