For many leaders preparing for CMMC, the hardest part isn’t the technical work—it’s understanding where their responsibility ends and their providers’ responsibility begins.
And that’s exactly why the Shared Responsibility Matrix (SRM) exists. It clarifies who owns each control, where evidence comes from, and how accountability is distributed among the Organization Seeking Certification (OSC) and its external partners.
Through this series, we’ve explored several controls that are often misunderstood—controls where leadership decisions, not technology, determine compliance success.
As a C3PAO, we’ve seen time and again that the OSC’s ability to describe and document its shared responsibility model is one of the best predictors of a successful assessment.
The SRM isn’t a paperwork exercise; it’s a reflection of your organization’s governance.
When assessors review it, we’re looking for signs that you:
If your SRM is vague or outdated, it tells us that your organization may be relying on assumption rather than structure. When it’s accurate and detailed, it shows maturity—and it often makes the assessment go smoother.
In every blog of this series, we’ve seen a pattern emerge: providers can enforce, configure, and monitor, but only the OSC can decide.
Each of these reinforces the same idea: you can delegate work, but you can’t delegate ownership.
With CMMC Level 2 assessments moving forward, the Department of War has made clear that self-attestation is no longer enough. The transition to third-party validation happened because too many organizations documented compliance but never verified it.
CMMC is about trust—and trust must be demonstrated.
That’s where shared responsibility becomes so powerful. When you can show that your organization understands the difference between provider duties and internal accountability, you’re not just proving compliance; you’re showing the maturity that CMMC was designed to measure.
A clean, detailed SRM and well-documented processes don’t just help you pass an audit. They build the muscle memory your organization needs to sustain cybersecurity in the long run.
CMMC is, at its heart, a leadership framework disguised as a security standard.
It requires organizations to make deliberate, risk-informed decisions—to define policies, own processes, and hold partners accountable.
That’s not work you can outsource. It’s leadership in action.
And it’s the reason successful OSCs approach compliance as a team sport, where everyone knows their role.
At MNS Group, we see this every day. Our most successful clients are the ones who don’t just hire us to “make them compliant.” They engage with us to understand compliance—to build confidence in their program and to make smart, sustainable decisions that protect their people, their contracts, and their future.
Your service providers play a vital role. Your C3PAO validates your maturity. But ultimately, your organization leads the effort.
The clearer you define your responsibilities—and the more you embrace your ownership—the stronger, more resilient, and more compliant your business becomes.
That’s what shared responsibility really means.
It’s not about dividing the work; it’s about aligning the mission.