What Is a 3PAO?

You want to sell your cloud service to a federal agency, and someone said you need a 3PAO.

That is fair, because a FedRAMP authorization needs an independent assessor. (Partners in the Authorization Process)

What the name means

A 3PAO is a Third Party Assessment Organization.

FedRAMP is the Federal Risk and Authorization Management Program.

It is the government-wide program that sets the security standard for cloud services the government buys. (A2LA FedRAMP 3PAO program)

Think of a 3PAO as the independent tester FedRAMP relies on.

It checks a cloud service against the FedRAMP baseline controls.

Then it writes down what passed, what failed, and what risk remains.

What a 3PAO does in an authorization

FedRAMP says a 3PAO performs initial and periodic assessments of cloud systems.

The point is to check that the system meets FedRAMP requirements. (Partners in the Authorization Process)

One job is the readiness review.

A CSP is a Cloud Service Provider.

Its service is called a CSO, a Cloud Service Offering.

For the review, a CSP works with a FedRAMP recognized 3PAO. (Rev5 Agency Authorization)

The 3PAO writes a Readiness Assessment Report.

A RAR is a Readiness Assessment Report.

It documents how ready the service is to meet federal security requirements. (Rev5 Agency Authorization)

The other job is the full assessment.

The 3PAO runs the tests and writes the report.

That report is the SAR, the Security Assessment Report.

FedRAMP says the 3PAO is responsible for developing the SAR. (Security Assessment Report)

The SAR documents the test results for the CSO.

It includes a summary of the risks that remain when testing ends.

It also holds scan results, test findings, and the penetration test report.

The 3PAO signs the SAR and gives its authorization recommendation. (Security Assessment Report)

How a firm becomes a 3PAO

Not just any security firm can do this work.

Under the FedRAMP framework, 3PAOs must be accredited by A2LA to be recognized. (A2LA FedRAMP 3PAO program)

A2LA is the American Association for Laboratory Accreditation.

Its process evaluates the firm's technical competence.

It also checks compliance with ISO/IEC 17020.

ISO/IEC 17020 is the international standard for bodies that perform inspections.

A firm must also spend at least a year in A2LA's Cybersecurity Inspection Body Program before it is considered. (A2LA FedRAMP 3PAO program)

Once recognized, the 3PAO is listed on the FedRAMP Marketplace. (FedRAMP Marketplace Assessors)

Why independence is the whole point

A CSP cannot grade its own homework.

The whole model rests on a tester with no stake in the outcome.

FedRAMP recognized 3PAOs must meet quality, independence, and knowledge requirements. (Partners in the Authorization Process)

That is why agencies trust the report.

What to do this week

Decide whether you need a readiness review or a full assessment.

Check the FedRAMP Marketplace for the current list of recognized 3PAOs. (FedRAMP Marketplace Assessors)

Confirm the firm is still listed before you sign anything.

Ask what the 3PAO needs from your team to start testing.

Sources

• FedRAMP, Rev5 Agency Authorization (Readiness Assessment): https://www.fedramp.gov/rev5/agency-authorization/
• FedRAMP documentation, Security Assessment Report (SAR), marked by FedRAMP as legacy reference during the 2026 transition: https://github.com/fedramp/docs-legacy/blob/HEAD/content/playbook/csp/authorization/sar.md
• FedRAMP documentation, Partners in the Authorization Process, marked by FedRAMP as legacy reference during the 2026 transition: https://github.com/fedramp/docs-legacy/blob/HEAD/content/playbook/csp/authorization/partners.md
• A2LA, FedRAMP Third-Party Assessment Organizations (3PAO): https://a2la.org/accreditation/fedramp/
• FedRAMP Marketplace, Assessors: https://fedramp.gov/marketplace/assessors

Next step

Preparing for a 3PAO assessment means collecting clean evidence from your live cloud environment.

PolicyCortex uses 33 collectors that read live Azure configuration.

It builds SSP, SAR, and POA&M output from the evidence it collects. See how it works.