According to the CMMC Assessment Process (CAP) and the roles defined within the CMMC Ecosystem, the responsibility for the final determination of assessment findings rests with the C3PAO (Certified Third-Party Assessment Organization).
While the Assessment Team (Lead Assessor and Assessor) performs the legwork—conducting interviews, examining documents, and testing mechanisms—the C3PAO is the legal entity contracted by the OSC (Organization Seeking Certification) to conduct the assessment and issue the recommendation for certification.
Role of the C3PAO: The C3PAO provides the quality assurance and oversight. Once the Assessment Team completes the draft findings, the C3PAO performs a quality or "peer" review to ensure the findings are consistent with CMMC requirements. They hold the final authority over the Recommended Finding (Met, Not Met, or N/A) before it is uploaded to the eMASS (Enterprise Mission Assurance Support Service) or the designated DoD database.
Role of the Cyber AB (formerly CMMC-AB): The Board provides the accreditation for the C3PAOs and manages the ecosystem, but they do not participate in individual assessments or overrule specific technical findings of an assessment unless there is a formal appeal or ethics complaint.
Role of the Assessment Team Members: They collect evidence and make initial determinations, but their findings are subject to the C3PAO’s internal quality management system (QMS) review.
Role of the OSC Sponsor: The OSC is the entity being assessed; they have no authority over the interpretation of findings, though they may provide additional evidence during the remediation period.
Reference Documents:
CMMC Assessment Process (CAP) v1.0: Section on "Phase 3: Conduct Assessment" and "Phase 4: Reporting Results," which details the C3PAO’s responsibility for the final package.
C3PAO Authorization Requirements: Outlines the requirement for a quality management review of all assessment findings by the C3PAO before submission to the DoD.