One of the most striking reforms to the Cybersecurity Maturity Model Certification (CMMC) framework was the introduction of mandatory C3PAO-led audits for organizations seeking assessments (OSAs) at Level 2.  

Short for CMMC third-party assessor organizations, C3PAOs are the official entities mandated by the United States Department of Defense (DoD) to undertake Level 2 cybersecurity audits. These agencies are approved by the Cyber Accreditation Body (Cyber AB), with a list of duly credentialed assessors listed on the Cyber AB’s marketplace.  

Note that Level 2 defense contractors can undertake internal cybersecurity audits whenever they please. However, the DoD requires all mandatory assessments (which should be scheduled triennially) to be spearheaded by C3PAOs.   

The fact that all C3PAOs must be approved by Cyber AB – the sole accreditation body for the entire CMMC ecosystem – is excellent news for any Defense Industrial Base (DIB) organization seeking to conduct objective cybersecurity assessments.  

But since each organization is unique, due diligence is critical when scouting for the right assessor. And after finding a suitable C3PAO, it’s also prudent to plan ahead before scheduling a live assessment.  

Here’s a C3PAO hiring checklist and how to prepare for each evaluation.    

How to Choose A C3PAO?

Choosing a C3PAO can be a serious undertaking, particularly for new defense contractors. But by following the below pointers, you can quickly hone in on an auditor that suits your company’s needs.

1. Scout Early Enough

The CMMC framework mandates C3PAO-led assessments triennially. That means each certification is only valid for three years.  

But due to the acute shortage of C3PAOs, it’s prudent to start scouting at least six months before your intended assessment date.  

Head to the Cyber AB marketplace and select an accredited C3PAO. Ensure the agency is duly credentialed, not merely listed on the platform. Starting early also entails setting aside the necessary resources. Assessment costs and timelines will vary significantly, depending on your organization’s size and the expected scope of the audit. 

Remember to also allocate the right personnel. Although C3PAOs are competent enough to undertake CMMC Level 2 audits, collaborating with your in-house cyber team can help expedite the assessment process. 

2. Insist On Niche-specific Experience

To become a C3PAO, organizations must demonstrate in-depth knowledge of the CMMC framework and other cybersecurity programs. Therefore, anyone listed on the Cyber AB is already duly qualified for the job.  

However, it’s best to choose someone with extensive experience auditing contractors in your niche.  

An agency that has evaluated similar companies would be privy to the compliance pitfalls your business likely faces, enabling it to craft tailored solutions.  

Better yet, choose an organization that’s familiar with your stack. This ensures seamless software integration and data visualization, both of which are critical in speeding up Level 2 audits. 

3. Multi-industry Expertise Is Encouraged Too

There are several other cybersecurity frameworks besides CMMC.  

Noteworthy examples include the State Risk and Authorization Management Program (StateRAMP) and the Federal Risk and Authorization Management Program (FedRAMP®).  

Although you’re seeking to audit for CMMC Level 2 compliance, it’s best to choose someone with experience in these other frameworks. It helps streamline the assessment process, especially if your organization handles information that straddles several cybersecurity programs.  

4. Check for Technical Qualifications

While aspiring C3PAOs undergo a rigorous accreditation process, it’s best to ask for proof of technical qualifications.  

For starters, all C3PAOs should possess a DUNS number. The organization must also be registered in the United States and have proof of liability insurance.  

Other technical qualifications are not necessarily required by the Cyber AB, but can be critical in pointing you to a qualified assessor.  

An example is the Certified Information Systems Security Professional (CISSP) certification.

5. Look For Security Clearance

Hiring a C3PAO means entrusting your company’s secrets to a third party. Therefore, you require an agency that can be trusted with such sensitive information.  

Look out for someone with proper security clearance, such as the Homeland Security (DHS) Suitability clearance. This provides peace of mind, knowing the organization will handle all information in strict adherence to applicable data privacy laws.

6. Read Customer Reviews

Reviews can also play a key role in pointing you to a qualified C3PAO.  

Sample online testimonials on reputable review platforms, such as Google Reviews or Trustpilot, to learn about the experience previous defense contractors had with a C3PAO before hiring the organization.  

How responsive is the assessor’s support? Does the agency take forever to complete audits? What about their fees?  

Reading customer reviews can offer insights into such questions, enabling you to hone in on the right auditor. 

How to Prepare For C3PAO Assessments?

Preparing for C3PAO assessments ahead of time can help streamline the audits.  

Early preparation minimizes operational downtimes during the evaluation process. It also helps manage assessment costs, which can run into hundreds of thousands, depending on your company’s scale and structure.  

1. Determine That You Require C3PAO Audits

Not all defense contractors require C3PAO-led audits. So, how do you determine the best CMMC assessment for your needs?  

Before seeking out a C3PAO, ensure you’re a Level 2 business. Level 2 applies to defense contractors that handle Controlled Unclassified Information (CUI). It differs from Level 1, which only targets companies that manage Federal Contract Information (FCI).  

Note that CMMC Level 2 certification is mandatory for Level 3 clearance. If you’re applying for Level 3 status (particularly for the first time), you’ll need C3PAO audits to validate your compliance with all Level 2 controls.  

You can then proceed to contact the Defense Industrial Base Cybersecurity Assessment Center (DIBCAC) for a dedicated Level 3 assessor.

2. Know What C3PAOs Typically Look For

C3PAO audits may stretch into weeks or months. However, you can shorten the process significantly if you understand what these agencies typically look for.  

Those include; 

Access Control Protocols

The DoD requires all defense contractors to implement robust access control protocols. These procedures ensure that Controlled Unclassified Information is accessible only to duly credentialed personnel, and preferably on a need-to-know basis.  

A C3PAO will carefully review your organization’s assets to establish if your access control protocols align with the CMMC framework.  

Focus areas range from basic password management techniques like multi-factor authentication (MFA) to more sophisticated ones like data encryption.  

Incident Response Protocols

No one wishes to deal with cyber-attacks after the fact. But once these events occur, you can leverage your incident response protocols to mitigate their impact and restore your business to full functionality.  

Before hiring a C3PAO, ensure your incident response controls are up to scratch. A good practice is to align these protocols with the CMMC framework.  

Now, you may never gauge the efficacy of your organization’s incident response mechanisms until actual risks occur. Obviously, you don’t wish for things to get to that level. A more proactive approach would be to simulate your incident response protocols regularly. 

Data Flow Diagrams

Data flow refers to the pathways that information follows as it enters and exits your organization.  

A weak data flow regime can lead to dangerous exfiltration of highly sensitive defense secrets, which explains why this is another critical area that C3PAOs usually target.  

Both FCI and CUI typically come with defense contractors. Once you’ve acquired this information, it’s important to store, manage, and disseminate it (where applicable) in accordance with the CMMC requirements.  

 3. Conduct a Gap Analysis

One of the costliest mistakes for CMMC Level 2 businesses is relying solely on the mandatory triennial audits. Because hackers are always waging aggressive attacks on the defense supply chain, it’s prudent to conduct as many internal cybersecurity assessments as reasonably possible.  

Routine audits are particularly critical ahead of actual C3PAO-led evaluations. They let you uncover security vulnerabilities and address them before the mandatory audits, improving the outcome of each assessment.  

There’s no hard-and-fast rule on how frequently to conduct routine CMMC gap analyses. However, many experts recommend biennial audits.  

Just ensure these assessments don’t overlap with mandatory C3PAO evaluations. Besides, regular audits are paramount even if you reckon your cybersecurity posture is spot-on. 

You can tap into your in-house cyber team to conduct rigorous gap analysis. But if you’re looking for unbiased audits, you could consider outsourcing independent assessors.  

4. Implement the Relevant Controls

If a preliminary analysis uncovers glaring vulnerabilities in your information systems, take the necessary measures to seal those loopholes.  

This will ensure that live audits turn up fewer or no gaps, accelerating the CMMC certification process.  

Remember to refer to the CMMC security controls for Level 2 businesses when remediating security weaknesses. 

5. Update Cybersecurity Documents

Each CMMC audit must culminate in an update of existing security documents. C3PAOs will review these records for insights into your organization’s cybersecurity posture.  

At the very least, ensure your business has a System Security Plan (SSP) and a Plan of Action and Milestones (POA&Ms).  

An SSP highlights your organization’s overall CMMC preparedness. It spells out the security protocols you’ve implemented to proactively avert cyber-attacks.  

Since the focus is CMMC Level 2, ensure your SSP captures risk prevention and mitigation measures for safeguarding Controlled Unclassified Information.  

Meanwhile, POA&Ms detail the security gaps detected in previous assessments and a roadmap for remediating them. The document also outlines the responsible personnel and the milestones for sealing the security gaps. 

 

Get Ahead Of the Queue by Enlisting Professional C3PAO-Led Assessments 

As of mid-2025, there were approximately 80 fully authorized CMMC third-party assessor organizations. That represents an acute shortage when you consider there’s an estimated 80,000 defense contractors expected to obtain their Level 2 CMMC certifications by Q4 of 2026.  

Prioritizing C3PAO assessments is the surest way to get ahead of CMMC compliance. However, the quest for urgent audits shouldn’t discredit the significance of preliminary preparations.  

Start by choosing the right C3PAO for your business.  

While there are several options to explore on the Cyber AB marketplace, insist on an agency with relevant industry experience. That means the organization must have audited several defense contractors offering similar services to your business.  

You’ll also need someone who’s familiar with your stack, as this can shorten the assessment process considerably.  

After finding a suitable C3PAO, conduct preliminary preparations to assess your audit readiness.