The Department of Defense (DoD)’s Cybersecurity Maturity Model Certification (CMMC) became effective Dec 2024. It’s designed to ensure that government contractors maintain strong cybersecurity practices when handling Controlled Unclassified Information (CUI) and Federal Contract Information (FCI). 

A key part of the CMMC ecosystem is the CMMC Third-Party Assessment Organization (C3PAO), which conducts independent assessments of companies to ensure compliance with CMMC requirements. Whether you are looking to become a C3PAO or need a C3PAO to perform your CMMC assessment, this guide will provide everything you need to know.

What is a C3PAO?

A C3PAO (CMMC Third-Party Assessment Organization) is an entity accredited by the Cyber AB to conduct official CMMC assessments. These organizations are responsible for evaluating organizations seeking certification (OSCs) to determine if they meet the necessary cybersecurity standards mandated by CMMC. 

C3PAOs employ trained Certified CMMC Assessors (CCAs) and Certified CMMC Professionals (CCPs) who conduct assessments based on the CMMC Assessment Process (CAP) guidelines. The role of a C3PAO is critical, as their assessments determine whether a company achieves CMMC, and can therefore bid on and maintain government contracts that involve Controlled Unclassified Information (or CUI).

Why Are C3PAOs Important?

  • Ensuring Compliance: C3PAOs verify that defense contractors follow CMMC-required cybersecurity practices, reducing the risk of cyber threats.
  • Standardized Assessments: As independent third parties, C3PAOs ensure assessments are consistent and objective.
  • Securing the Supply Chain: By enforcing strong cybersecurity measures, C3PAOs help strengthen the DIB’s resilience against cyberattacks.

Details of a C3PAO CMMC Assessment

A C3PAO-led CMMC assessment is a structured process that evaluates whether an organization meets the cybersecurity requirements for its required CMMC level 2. The assessment process typically follows these stages:

1. Pre-Assessment Preparation

Before engaging a C3PAO, an organization should conduct an internal review to identify cybersecurity gaps. Many companies hire a Registered Practitioner (RP) or CMMC consultant to help prepare.

2. Readiness Review with C3PAO

Investing in a CMMC Assessment, you will want to know exactly how much you will need to spend in time and money to meet compliance standards. Moving forward in the process without knowing the costs that might arise can cause unwanted financial concerns, so a readiness review with a C3PAO is a smart idea.

3. CMMC Assessment 

Once an OSC is ready, the formal C3PAO assessment begins:

  • Initial Documentation Review: Assessors review policies, procedures, and system security plans (SSP).
  • Interviews with Key Personnel: The C3PAO interviews employees responsible for cybersecurity policies and implementation.
  • Testing Security Controls: The C3PAO validates cybersecurity measures by observing system operations.
  • Remediation Period (if needed): If the OSC falls short of the necessary 110 requirements, they  have 10 days post-assessment to correct any deficiencies regardless of what the score is. During this 10 day period, they should strive to achieve a 110 if possible to avoid paying for a follow-up close out assessment. If the OSC can’t get to a 110, they should attempt to at least achieve 88 and not miss any of the required controls. So long as they do this, the OSC is then afforded 180 days to finalize any gaps and get to a 110.
  • Final Assessment Report: The C3PAO provides a report to the Cyber-AB, which then determines certification status.

4. Certification and Beyond

  • If an OSC passes, the certification remains valid for three years, with annual self-attestation.
  • If an OSC fails, it must remediate deficiencies and reapply for a new assessment.

How to Become a C3PAO

If your organization wants to become a C3PAO, you must meet Cyber-AB’s eligibility requirements and follow these steps:

1. Meet Initial Requirements

  • Your company must be legally registered in the United States.
  • You must undergo a Foreign Ownership, Control, or Influence (FOCI) evaluation.

2. Apply for C3PAO Status

  • Submit an application to Cyber-AB.
  • Complete a background check.
  • Provide proof of liability insurance.

3. Hire Certified Assessors

To become a C3PAO, your organization must meet the minimum staffing requirements provided by the Cyber-AB. 

4. Pass a DIBCAC Assessment

The Defense Industrial Base Cybersecurity Assessment Center (DIBCAC) must validate that your organization meets security standards in order to achieve CMMC Level 2 compliance.

5. Pay Fees and Maintain Compliance

C3PAOs must pay annual fees to Cyber-AB and renew certifications regularly.

How to Choose a C3PAO for Your CMMC Assessment

Choosing the right C3PAO is crucial to a smooth CMMC assessment. Here’s what you should consider:

1. Verify Accreditation

Ensure the C3PAO is officially listed in the Cyber-AB Marketplace to confirm accreditation.

2. Consider Industry Experience

Look for C3PAOs with experience in your specific industry to ensure they understand the unique cybersecurity challenges in your sector.

3. Evaluate Their Assessment Approach

Some C3PAOs offer pre-assessment readiness services, while others focus only on final assessments. Clarify what is included before signing a contract.

4. Check for Conflicts of Interest

A C3PAO cannot assess your company if it has previously provided consulting services to you.

5. Compare Costs and Timelines

C3PAO assessments can be expensive. Get multiple quotes and consider assessment timelines before choosing. 

Top C3PAOs

The best C3PAO for your company is probably going to be one familiar with your tech stack, ensuring they have the expertise to meet compliance and move through the process smoothly. 

If you’re a PreVeil customer, check our Partner Marketplace for Preferred C3PAOs. Each is certified by the CyberAB and vetted by our compliance team, so they’re familiar with our technology and documentation, which saves you time & money.

Learn More about CMMC 

A CMMC certification is essential for government contractors handling CUI and FCI, and C3PAOs play a crucial role in ensuring compliance. Whether you’re seeking CMMC certification or considering becoming a C3PAO yourself, understanding the CMMC assessment process, requirements, and available C3PAOs will help you navigate the system successfully.If you’re ready for a CMMC assessment, start researching accredited C3PAOs today to ensure you meet DoD compliance requirements!