What Happens During a FedRAMP 3PAO Assessment

A Third Party Assessment Organization (3PAO) is an independent company accredited by the American Association for Laboratory Accreditation (A2LA) to conduct FedRAMP assessments. The 3PAO performs the technical and procedural assessment of your cloud service, produces the Security Assessment Report (SAR), and submits the package for agency or JAB review.

3PAOs are not consultants. They do not help you implement controls. The line between consulting and assessment is strict. If a 3PAO designs your security program, they cannot also assess it. Some firms have separate consulting and assessment practices to provide both services without the conflict.

FedRAMP publishes the list of accredited 3PAOs. Selection criteria include: A2LA accreditation, FedRAMP experience, industry experience relevant to your CSO, and references. Costs vary widely based on scope.

For framework basics, see the FedRAMP framework guide.

The planning phase runs 4-8 weeks before fieldwork begins. Activities include:

• Security Assessment Plan (SAP): The 3PAO writes a SAP describing the assessment approach, scope, methods, and timeline. The SAP is reviewed by the sponsoring agency.
• Test plan development: Specific test procedures for each control. Testing methods include examine (review evidence), interview (talk to personnel), and test (perform technical verification).
• Logistics: On-site dates, remote access requirements, assessor team composition, points of contact
• Pre-fieldwork document review: 3PAO reads SSP, supporting policies, and other documentation. Identifies questions and clarifications before fieldwork.

Many CSOs underestimate the planning phase. Skipping or rushing planning leads to fieldwork problems: undefined boundaries, unclear test methods, and gaps in evidence. Treat the SAP as a contract for what fieldwork will cover.

Fieldwork is the core of the assessment, running 4-12 weeks depending on scope. The 3PAO conducts three types of testing:

1. Examine testing: Review configuration files, audit logs, policy documents, network diagrams, and other evidence artifacts. Most controls have at least one examine procedure.
2. Interview testing: Structured interviews with personnel responsible for control operation. Roles interviewed: system administrators, security operations, incident response, change management, executive sponsor.
3. Technical testing: Hands-on verification. The 3PAO logs into systems and verifies controls operate as documented. This includes vulnerability scanning, configuration verification, and penetration testing.

Fieldwork includes mandatory penetration testing of the authorization boundary. The 3PAO conducts external and internal pen testing using FedRAMP-aligned methodology. Findings from pen testing are documented in the SAR.

During fieldwork, the 3PAO and CSO meet regularly to discuss preliminary findings. Address issues immediately rather than waiting for the SAR.

After fieldwork, the 3PAO writes the SAR. This takes 6-12 weeks. The SAR contains:

• Executive summary: Overall assessment results and risk posture
• Test results for every control: Pass, partially passed, or failed, with rationale
• Findings: Each finding with severity rating (High, Moderate, Low), description, evidence, and recommendation
• Penetration test results: Detailed pen test findings and exploit paths
• Risk assessment: Aggregate risk based on findings

Findings drive the POA&M. Each finding becomes a POA&M item with remediation plan and target date. Some findings can be remediated during the assessment period and are resolved before the SAR is finalized. Others remain open in the POA&M for post-authorization closure.

The CSO has opportunity to respond to the SAR. The 3PAO then issues a final SAR with the CSO responses incorporated. Submission goes to the sponsoring agency for authorization decision.

After SAR delivery, several activities continue in parallel:

• Agency review: Sponsoring agency security team reviews SAR, requests clarifications, may identify additional risks
• POA&M finalization: CSO and agency agree on POA&M items, dates, and risk acceptance for high-risk findings that cannot be remediated immediately
• Authorization decision: Agency authorizing official issues ATO if risks are acceptable, or requires additional remediation before authorization
• 3PAO availability: 3PAO remains available for follow-up questions during agency review (typically 30-60 days)

Total time from end of fieldwork to ATO issuance: 3-6 months in most cases. Agency review timing is the largest variable. Some agencies move faster than others. Larger agencies with formal review boards can take longer than smaller agencies with streamlined processes.

If authorization is granted, post-authorization continuous monitoring begins immediately. The 3PAO may also conduct the annual assessment in subsequent years.