Many defense contractors still believe that CMMC Level 2 certification is solely an evaluation of their internal cybersecurity controls. This assumption can lead to costly surprises.
If your organization relies on a Managed Service Provider (MSP) or Managed Security Service Provider (MSSP) to support its systems or security functions, those providers are very much in scope for the Cybersecurity Maturity Model Certification (CMMC) assessment. These third parties, formally known as External Service Providers (ESPs), can directly influence your compliance posture.
Assessors will likely ask how these vendors contribute to meeting NIST 800-171 requirements, whether they interact with Controlled Unclassified Information (CUI), and if they can support evidence-based claims about security controls. If your MSP or MSSP isn’t prepared, that risk falls squarely on you.
It is not enough to trust your provider. You need to validate that they are part of your compliance readiness strategy; early and often.
That includes your MSP, MSSP, or any cloud or IT vendor responsible for core systems or security functions.
The Department of Defense and Cyber AB have made it clear: if an ESP affects the confidentiality of CUI, it must be held to the same compliance standard. That means your providers need to be prepared to demonstrate how their controls align with the framework, and you need to ensure they are.
When a CMMC Level 2 assessment begins, it is not just your policies and internal teams under review. If your service providers interact with CUI systems or environments, assessors will examine how their services contribute to (or detract from) compliance.
Expect requests for:
| Customer Responsibility Matrix (CRM) or Shared Responsibility Matrix (SRM) that define shared responsibilities | |
| Control evidence that demonstrates proper logging, monitoring, encryption, and access management |
Assessors may also want to speak directly with your provider, primarily if their services cover incident response or system hosting. If your MSP or MSSP is unfamiliar with CMMC expectations or cannot clearly explain their security practices, it may reflect poorly on your organization.
One of the most common pitfalls during a CMMC assessment is assuming your provider “has it covered.”
That’s a risky bet.
Assessors don’t accept vague claims or verbal reassurances. They require documented evidence that demonstrates how your provider supports the confidentiality of CUI.
This might include:
| Control-to-service mappings |
|
| Architectural diagrams of hosted environments | |
| Logs or incident reports tied to detection and response procedures | |
| Encryption policies and key management processes |
More importantly, your provider needs to be able to explain this evidence and connect it to relevant CMMC practices.
If you haven’t had this conversation with your MSP or MSSP yet, now is the time. It is far easier to fill evidence gaps before the assessment than to scramble under pressure when assessors are on-site or meeting with you virtually.
Not every service provider is equipped to support a compliance-driven environment. Even if your MSP or MSSP excels at maintaining systems and preventing downtime, that doesn’t guarantee they’re prepared for a CMMC assessment.
When evaluating your providers, ask questions like:
| Are you familiar with CMMC Level 2 and NIST 800-171? | |
| Can you provide documentation that maps your services to the required controls? | |
| Have you supported other defense contractors through a CMMC Level 2 certification assessment or a CMMC readiness engagement? | |
| Are you a CMMC Registered Provider Organization (RPO)? | |
| Do your SLAs and security procedures align with DFARS 7012 requirements? |
Look beyond technical capabilities. A reliable provider should articulate how their processes, tools, and teams directly contribute to your compliance posture. They must be willing to collaborate during the assessment and speak with assessors if needed.
You are not just hiring a vendor; you are partnering with a security extension of your own organization. Ensure they understand their role in achieving your compliance outcome and are willing to collaborate with assessors as needed.
At MAD Security, compliance isn’t an afterthought; it is embedded in everything we do.
As a CMMC Registered Provider Organization, we help defense contractors achieve and maintain readiness through proven, security-focused services.
Our team understands the intricacies of CMMC Level 2 and is fluent in the language of NIST 800-171. But we go beyond checklists. We implement and manage the controls required for certification across key services like security monitoring, incident response, endpoint protection, and vulnerability management.
We’ve supported clients through CMMC Level 2 certification assessments and worked directly with assessors to provide the documentation and assurance needed to succeed.
Whether managing your security operations or closing compliance gaps, we bring the clarity, experience, and technical rigor needed to pass assessments with confidence.
The solution is simple: engage them early, ask the right questions, and work with partners who understand the stakes. A well-prepared provider can ease the burden of certification and help you demonstrate the maturity your environment demands.
Your external service providers play a critical role in your certification outcome. If they aren’t ready, neither are you.
MAD Security helps defense contractors ensure their MSPs and MSSPs are fully prepared to support assessment requirements. We work directly with clients and assessors to streamline evidence collection, map services to compliance controls, and close readiness gaps.
Schedule a CMMC Readiness Consultation with our team today and take the next step toward confident, audit-ready compliance.
Original Publish Date: December 23, 2025
By: MAD Security