A C3PAO (CMMC Third-Party Assessment Organization) is a company authorized by the Cyber AB and accredited under ISO/IEC 17020 to conduct official CMMC Level 2 certification assessments of defense contractors. Only a C3PAO listed on the Cyber AB Marketplace can issue the assessment that leads to CMMC Level 2 certification — consultants, MSPs, and RPOs cannot.
What a C3PAO actually does
A C3PAO fields a certified assessment team (Lead CCA plus assessors) that examines evidence, interviews staff, and tests a sample of the 110 NIST 800-171 controls in your scoped environment, then submits results into CMMC eMASS. Outcomes: certification (all controls met), conditional certification (minor POA&M-eligible gaps closed within 180 days), or failure.
C3PAO vs RPO vs consultant
| Role | Can prepare you | Can certify you | Conflict rule |
|---|---|---|---|
| C3PAO | Limited | Yes — Level 2 certification assessments | Cannot assess a company it consulted for |
| RPO (Registered Provider Organization) | Yes — readiness, remediation, SSP | No | Advisory only |
| Consultant / MSP | Yes | No | No Cyber AB vetting unless RPO |
The same firm can never both prepare and certify you — plan two vendors from day one: a readiness partner, then a C3PAO.
How to choose a C3PAO
Book 6-12 months ahead (capacity is thin — a few hundred C3PAOs for tens of thousands of contractors needing certification). Ask: how many Level 2 assessments completed, sector experience (manufacturing OT vs SaaS), how they price scope creep, their view on your enclave boundary, and whether they’ll run a readiness review call before you sign. Verify the listing on the Cyber AB Marketplace yourself. Full pricing detail: C3PAO certification cost breakdown.
What a C3PAO assessment costs
Typical SMB Level 2 assessments run $40-120k for the assessment itself depending on scope, locations, and evidence quality — and the assessment is only 25-40% of total certification cost once remediation and documentation are counted. Model your full number in the cost & roadmap planner or the CMMC Cost Index.
Does the Phase II suspension change this?
The 2026 Phase II review paused new contractual requirements for third-party certification, but C3PAO assessments continue, early slots are cheaper than panic-season slots, and DFARS 7012/7019 self-assessment duties never paused. Details: CMMC Phase 2 suspension explained.
Frequently asked questions
How many C3PAOs are there?
A few hundred authorized organizations, listed on the Cyber AB Marketplace — against an estimated 70-80k defense contractors ultimately needing Level 2. That mismatch is why booking windows matter more than price alone.
Can a non-US company use a C3PAO?
Yes. Non-US suppliers handling CUI can be assessed; logistics (travel, language, data-residency, US-persons issues for ITAR) add cost. Our CMMC international guide covers the specifics.
Can a C3PAO also be my consultant?
Not for the same engagement — conflict-of-interest rules prohibit assessing an environment they helped build. Use an RPO or readiness firm first, then an independent C3PAO.
What happens if I fail?
POA&M-eligible items (limited, low-weight controls) give you 180 days to close gaps for conditional certification; larger failures mean re-assessment. A mock assessment beforehand is far cheaper than a failed real one.
Know your number before a C3PAO does.Get assessment-ready →
Fixed-fee readiness, evidence packs, mock assessment.
ITSECOPS is a readiness partner (not a C3PAO) serving defense suppliers in the US, Europe, and Asia. Informational, not legal advice.