Scheduling & Preparing for a C3PAO Assessment: Key Steps & Checklist

Get Ready for Your CMMC Level 2 CertificationTwo people work at a desk with documents, a calculator, and a small house model. One points to a bar graph, indicating analysis or discussion.

For government contractors handling Controlled Unclassified Information (CUI), passing a Cybersecurity Maturity Model Certification (CMMC) Level 2 assessment is a critical milestone. This assessment, conducted by a Certified Third-Party Assessment Organization (C3PAO), verifies your compliance with NIST SP 800-171 security requirements, an essential step to maintaining or securing Department of Defense (DoD) contracts.

But the process of scheduling and preparing for a C3PAO assessment can feel overwhelming. When should you schedule? How do you prepare? What happens if you don’t pass? This guide will walk you through key steps to ensure a smooth, successful assessment and help you choose the right C3PAO for your business.

When Should You Schedule a C3PAO Assessment?

Timing is everything when it comes to CMMC certification. A well-planned schedule ensures you have enough time to identify gaps, remediate issues, and avoid delays that could impact your contract eligibility.

How far in advance should you schedule?

Most C3PAOs are in high demand, and lead times commonly range from three to six months. It’s best to schedule your assessment as soon as you’re confident in your compliance readiness—or even sooner if you want to secure a spot on their calendar while finalizing preparations.

How long does the assessment take?

The assessment process is broken down into 4 phases.

  • Plan and Prepare the Assessment – During this phase, the C3PAO will identify key contacts, finalize scope, complete pre-assessment documentation, and conduct a readiness analysis to determine if the organization is prepared to proceed.
    • Based on the organization’s size and scope, this can vary from a few weeks to months.
  • Conduct the Assessment – During this phase, the C3PAO will interview key personnel, collect documentation, and evaluate compliance with CMMC Level 2 requirements using the DoD’s assessment guide and scoring methodology.
    • This typically takes place over one or two weeks.
  • Report Results – During this phase, the C3PAO will prepare a report detailing MET/NOT MET/NA statuses for each requirement, issuing either a Final or Conditional Level 2 (C3PAO) Certificate or a determination letter.
    • These will typically be provided within two weeks of completing the assessment.
  • POA&M Validation – If the assessment yields NOT MET findings, and the Organization has been issued a Conditional Level 2 (C3PAO) Status, this phase will include reviewing and addressing POA&Ms.
    • The organization will have a predetermined period of time, as defined by the 32 CFR Part 170 Rule.

Additional time may be needed for review, reporting, and any remediation actions if gaps are identified.

Can you do a pre-assessment?

Yes. Many organizations opt for a gap analysis or a CMMC readiness review before scheduling their official certification. While companies can conduct a readiness review internally, many choose to work with a certified Registered Practitioner Organization (RPO) like Alluvionic for an unbiased, expert evaluation. RPOs offer in-depth guidance, identify compliance gaps, and conduct mock assessments to ensure teams are fully prepared. Since your selected C3PAO cannot provide readiness support due to conflict-of-interest rules, partnering with an RPO ensures a clear separation of services and a smoother path to certification.

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How Much Does a C3PAO Assessment Cost?

The cost of a C3PAO assessment varies based on several factors, including company size, system complexity, and scope of assessment. However, for most small to mid-sized government contractors, a general estimated range is around $40,000 to $100,000. View the full price break-down on the Federal Register.

Factors That Influence Cost:Person in a white shirt uses a calculator and a laptop on a bright desk.

  • Company size – Larger organizations with multiple locations or complex IT environments will pay more.
  • Number of assets in scope – More systems processing Controlled Unclassified Information (CUI) increase assessment time and cost.
  • C3PAO selection – Rates vary between assessment organizations, so it’s important to compare at least three different C3PAOs before making a decision.

Beyond the C3PAO assessment, another key cost to consider is readiness support. Hiring an RPO for a readiness review adds an expense but significantly boosts confidence and increases the likelihood of passing the C3PAO assessment on the first attempt.

Will the Assessment Be Conducted On-Site, Remotely, or Both?A person sits at a wooden desk, engaging in a video call on a computer. Three participants are on screen, smiling and interacting, conveying a collaborative atmosphere.

The assessment format—remote, on-site, or a combination of both—will depend on your specific environment and security requirements.

  • Remote Assessments: Many assessments can be completed entirely remotely using secure video conferencing and digital evidence submission, especially for organizations with centralized IT environments.
  • On-Site Assessments: If your in-scope systems include physical security controls or specialized infrastructure, an on-site visit will be necessary to verify compliance.
  • Hybrid Approach: Some assessments may be conducted primarily remotely, with a brief on-site visit to confirm physical security measures.

When selecting a C3PAO, clarify whether your assessment will be remote, on-site, or a hybrid approach to ensure alignment with your organization’s needs.

Choosing the Right C3PAO: Interview at Least Three

Not all C3PAOs are created equal, and selecting the right one is critical to your success. The assessment process should be thorough but fair, and you want a partner who understands your business and industry.

Key Factors to Compare When Interviewing C3PAOs

✔ Experience with businesses of your size and industry
✔ Availability and lead time for scheduling
✔ Assessment approach—collaborative vs. strict assessor style
✔ Post-assessment support and guidance
✔ Cost and payment structure

Interview at least three C3PAOs before making your final decision. This ensures you get the best fit for your organization. When you’re ready to start your search, check the Cyber AB’s C3PAO directory. If you’re working with an RPO like Alluvionic before your audit, they can connect you to a vetted network of C3PAOs.

Download our C3PAO Comparison Scoring Checklist to streamline your selection process and compare your options effectively.

Preparing for Your C3PAO Assessment

Once you’ve scheduled your assessment, the next step is preparing your environment, documentation, and team.

1. Confirm Your Assessment Scope

A hand types on a laptop keyboard, with digital folder icons and a document floating above the screen.

Your C3PAO will assess only the in-scope systems—those handling CUI. Clearly define and document your assessment boundary to avoid unnecessary scrutiny of out-of-scope systems.

2. Gather Required Documentation

Be prepared to provide:

  • System Security Plan (SSP) – The foundation of your cybersecurity posture
  • Plan of Action & Milestones (POA&M) – Any outstanding issues and their remediation timeline
  • Policies & Procedures – Covering access control, incident response, and system monitoring
  • Network Diagrams & Asset Inventory – Clearly defining your IT environment

Preparing this documentation well in advance of your assessment helps avoid scheduling delays.

3. Train Your Team

Your IT and security teams should be ready to answer C3PAO questions on:

  • Identify weak points before the official assessment
  • Improve staff confidence in responding to assessor questions
  • Reduce the risk of failing on critical requirements

Multiple teams like HR, Marketing, Operations, and others may have a role in CMMC, so ensure each team understands their role and how they impact the controls.

4. Perform a Mock Assessment

Conduct an internal or third-party mock assessment using CMMC Level 2 assessment criteria. This helps you:

  • Identify weak points before the official assessment
  • Improve staff confidence in responding to assessor questions
  • Reduce the risk of failing on critical requirements

Performing a mock assessment is a key activity in building team confidence for the assessment.

What Happens After the Assessment?

How soon will you get results?

Your C3PAO will provide a summary report shortly following the assessment. If you pass, the C3PAO will upload results to the CMMC Enterprise Mission Assurance Support Services (eMass) database and issue a certificate stating your CMMC status.

What if you don’t pass?

If minor gaps exist, you may be able to use a Plan of Action & Milestones (POA&M) to address deficiencies within 180 days. If major issues arise, you may need a full reassessment.

Start Your C3PAO Selection Process Today

The right C3PAO can make or break your CMMC Level 2 certification journey. To make the best choice, interview at least three assessment providers and compare their experience, availability, and approach. Working with an RPO like Alluvionic helps ensure you’ve addressed all gaps, feel confident in your readiness, and gain access to our vetted partner network of C3PAOs, all while having an advocate to guide you from start to finish.

Download our C3PAO Comparison Scoring Checklist to help you evaluate and select the best partner for your assessment. Get your copy now!

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