Organizations that receive controlled unclassified information (CUI) through participating in US Department of Wa (DoW) contracts will soon need to undergo a rigorous third-party certification audit for compliance with the Cybersecurity Maturity Model Certification (CMMC) 2.0 standard at Level 2.

The auditors that perform these assessments are called a CMMC Third-Party Assessment Organizations (C3PAOs). You might think that C3PAOs are interchangeable, that “cheaper is better,” and/or that engaging with one should be low on your priority list. The certification audit is way down your CMMC project timeline, after all.

But for organizations seeking certification (OSCs) against CMMC, choosing a C3PAO is an important, long-term partnership decision that can have a big impact on your business and your CMMC experience, for better or worse. It is critical to perform due diligence when choosing a C3PAO. And while your CMMC Level 2 assessment could still be over a year away, there is no time to waste in identifying and building a relationship with a C3PAO that is right for you.

This article gives business and technical leaders all the essential points on choosing the right C3PAO.

Key takeaways

• A C3PAO is an accredited, independent organization authorized by the Cyber AB to conduct CMMC Level 2 compliance assessments leading to certification. Only auditors with Cyber AB authorization can conduct CMMC audits.
• To ensure impartiality and eliminate potential conflicts of interest, C3PAOs do not offer pre-audit consulting or implementation services.
• The DoW estimates that over 80,000 companies will need to undergo CMMC Level 2 certification but there are currently less than 100 C3PAOs. This adds up to a growing certification bottleneck and the prospect of lengthening audit lead times.
• CMMC Level 2 certification assessment costs are trending upward, with many small to midsized businesses (SMBs) paying around $75,000.
• Scheduling a CMMC Level 2 assessment starts with contacting the C3PAO directly. This will initiate the process of scoping your assessment, getting a cost estimate, etc.
• A reputable C3PAO will want to work closely with your org to make sure your certification attempt is likely to succeed.

What is a C3PAO?

Within the CMMC service provider ecosystem, a C3PAO is an accredited, independent organization authorized by the Cyber AB to conduct CMMC Level 2 compliance assessments for US defense industrial base (DIB) contractors. An official C3PAO audit is mandatory for DIB orgs to demonstrate to the DoW and its prime contractors that they can protect CUI and will soon be required for contract participation. Only C3PAOs can conduct CMMC Level 2 certification audits.

A CMMC Level 2 assessment consists of interviewing staff, reviewing policies and documentation, testing controls, and examining evidence of control operation. The C3PAO then reports its audit findings to the DoW, which awards conditional or final CMMC certifications. This regime of third-party oversight replaces the former process of self-attested compliance with NIST 800-171.

To become a C3PAO, an audit firm must meet strict guidelines, including being US-owned, undergoing extensive background checks, and passing a CMMC Level 2 assessment themselves. To ensure objectivity and avoid conflicts of interest at audit time, C3PAOs do not offer pre-audit guidance, consulting, or remediation services to OSCs they plan to later assess. This is the job of a Cyber AB authorized Registered Provider Organization (RPO) or non-registered third-party CMMC consultant.

Given the paramount importance of achieving and maintaining CMMC Level 2 certification, a C3PAO is a critical partner for defense suppliers that handle CUI. Selecting a compatible C3PAO will improve your assessment experience and could influence your final compliance report or even help your cybersecurity posture.

Why be proactive in lining up a C3PAO?

As of January 2026, there are only 97 C3PAOs registered in the Cyber AB’s CMMC Marketplace. Meanwhile, the DoW estimates that over 80,000 DIB orgs will need to achieve CMMC Level 2 certification by the end of the three-year phased CMMC rollout in November 2028.

It is advisable to schedule a CMMC Level 2 assessment at least 9 to 12 months in advance, as C3PAOs will be in increasingly high demand and backlogs are inevitable. Early adopters have the advantage of scheduling their certification assessment with the widest choice of C3PAOs and can avoid risky delays in receiving their CMMC Level 2 certification. Getting certified early also offers a competitive advantage in the eyes of DoW prime contractors, which are pushing suppliers to get certified and prove CMMC compliance.

What are top considerations for choosing a C3PAO?

It is recommended to compare at least three C3PAOs around costs, experience, methods, staffing, and availability. These are the most critical steps in choosing a C3PAO:

• Confirm that they are Cyber AB accredited with a valid listing on the Cyber AB’s official CMMC Marketplace.
• Confirm that they have extensive experience with cybersecurity compliance audits in general (e.g., FedRAMP, ISO 27001, SOC 2) and NIST 800-171 audits specifically.
• Ensure they have worked successfully with other DIB companies whose size and role parallel yours (e.g., small manufacturers working on weapons systems contracts).
• Evaluate their assessment process. What are typical timelines, audit methods, and post-audit deliverables.
• Ask about their staffing. Do they use full-time employees, contractors, or both? Review the credentials of their lead assessors and other staff who may participate in your audit.
• What is their estimated cost for a CMMC Level 2 assessment for your business specifically? And what does that include? Rates can vary significantly for equivalent services.
• Is there any potential for a conflict of interest? Consultants that offer to help clients with both CMMC preparation and assessment are creating a conflict of interest that violates CMMC guidelines.
• What would the process be if your company didn’t pass its initial certification audit?
• How long has the C3PAO been in business?
• Does the C3PAO use technology to streamline and accelerate the assessment process?
• Is it important that your C3PAO be physically nearby? This could help you save on travel expenses.
• How large are they? How many CMMC Certified Assessors (CCAs) and CMMC Certified Professionals (CCPs) do they have? Is their size a good match for yours?
• Can they provide references who are willing to speak with you? Do they have case studies and testimonials from companies like yours?
• If you sign on with them, when could your assessment take place? Where would you stand in their current queue?

The deeper a C3PAO’s experience, the more likely they can identify and help you address compliance issues upfront to reduce your noncompliance risk. A more experienced provider may also be more likely to offer valuable feedback to maintain compliance and continuously improve your cybersecurity posture as CMMC requires.

C3PAO practices to be viewed as red flags include:

• Offering assessments at far below market value. Less is not more when it comes to assessing and potentially reassessing your CMMC Level 2 compliance.
• Undue sales pressure. Driving toward a quick commitment decision is unprofessional and may inhibit you from making an informed decision.
• Questionable claims or guarantees. C3PAOs cannot legitimately promise or guarantee CMMC Level 2 certification.

What is a ballpark cost estimate for a C3PAO assessment at CMMC Level 2?

Each OSC has a unique CMMC roadmap yielding a unique audit cost, even from the same C3PAO. Costs also vary widely between the least and most expensive C3PAOs.

Factors with the greatest impact on your audit costs include:

• The size and complexity of your CUI environment
• Business size, complexity, and number of locations
• Specific services included in the contract
• Ancillary costs like transportation and accommodations for audit staff
• The C3PAO’s expertise and reputation
• Supply and demand factors around auditor availability and audit wait times

CMMC Level 2 certification assessments with a C3PAO currently cost on average somewhere between $30,000 to $100,000. But this is trending upward rapidly, with $75,000 now being a common starting point.

How do we schedule our CMMC 2.0 assessment?

Scheduling a CMMC Level 2 assessment starts with contacting the C3PAO directly to initiate the process of scoping your assessment, getting a cost estimate, approving an estimate, and scheduling the assessment. It is important to connect with several C3PAOs as part of your due diligence.

Prior to engaging with a prospective C3PAO, your business will have spent months preparing your environment. You will need to identify all your systems that handle CUI and/or federal contract information (FCI), assess your current state of compliance (e.g., with a gap assessment and/or internal CMMC audit), and possibly obtain readiness services from a RPO or other third-party consultant.

You’ll also need to document or update your CMMC controls and policies, including required documents like a System Security Plan (SSP). It’s also essential to collect objective evidence of control operation for a sufficiently long period prior to the C3PAO assessment.

No one in the DIB benefits from failed CMMC audits. A reputable C3PAO is unlikely to schedule an OSC’s audit unless it has a high probability of success.  Your C3PAO should insist on regular advance communication and checkpoints to avoid costly, time-wasting missteps.

Some of the milestones a C3PAO may want to see from OSCs include:

• A complete and updated System Security Plan.
• A compliance status report based on results of an internal compliance audit conducted using the NIST 800-171A Rev 2 scoring methodology. This should include a prioritized list of Plans of Action & Milestones (POA&Ms) to identify and close all compliance gaps prior to the C3PAO assessment.
• Demonstrating that your documentation, policies, procedures, log data, and other compliance evidence are available and accessible to them. Evidence also needs to cover a sufficient time period, and falling short could delay your assessment.

How can we get C3PAO referrals?

While all C3PAOs must go through the same rigorous application process to achieve accreditation, they vary widely in terms of cost, approach, experience, reputation, and other factors that may be important to you.

Where can you find information and advice to simplify your C3PAO due diligence and quickly shake out a short list of likely candidates? Here are some of the most useful sources:

• The Cyber AB’s CMMC Marketplace. As noted above, this is the official, one-stop directory that lists all the C3PAOs. These are the only entities authorized to perform CMMC Level 2 assessments.
• Your CMMC implementation consultant. If you are working with a CMMC RPO or other cybersecurity consulting organization, they will likely have direct experience sitting across the table from C3PAO auditors. They may have favorites they know they can work with, and perhaps others they would steer you away from.
• Your managed service provider (MSP). Depending on the depth of their cyber services, your MSP or MSSP may have worked with C3PAO firms on various assessments. They may offer valuable opinions that reflect their knowledge of your business and its IT. However, if your MSP is also a C3PAO, it would break CMMC conflict of interest rules for you to also use them as your CMMC certification auditor.
• Your peers in the DIB. Your colleagues and peers in other DIB organizations—especially those that have achieved CMMC Level 2 certification—may have recommendations or can share their C3PAO due diligence experiences.

Important sources of general information on choosing and working with a C3PAO and preparing for your CMMC Level 2 certification assessment include:

• The free National Defense-ISAC C3PAO Shopping Guide for SMBs. Every OSC will want to be familiar with this publication.
• The DoW Chief Information Officer (DoW CIO) website.
• The extensive Defense Industrial Base Cybersecurity Assessment Center (DIBCAC) contractor resource page.

What’s next?

If you are looking to get the jump on your CMMC Level 2 assessment, CBIZ Pivot Point Security can help you with critical tasks like scoping your CMMC environment, performing a gap assessment to identify your current compliance status, and help you identify and execute next steps.

As one of the first RPOs and a highly experienced cybersecurity consultant serving aerospace/defense and many other industries, CBIZ Pivot Point Security offers a full range of CMMC compliance services, led by certified experts with decades of collective practice. We have helped hundreds of organizations prove they are secure and compliant.

Contact us to start a conversation on how we can support your CMMC certification journey.