This is the part most contractors skip, and it is the part that actually gets assessed. You can configure a perfect tenant and still fail, because a C3PAO evaluates your System Security Plan and your ongoing process, not your Entra blades directly.
Start your System Security Plan
The SSP is what gets assessed. Every control you configured in the previous areas needs to be written down: how you meet it, and where the evidence lives. Capture it control by control. This is exactly the work Readyline turns into an audit-ready SSP, and the steps you complete in our free Autopilot transfer straight into your control set.
Establish a risk-assessment cadence (3.11.1)
NIST 800-171 3.11.1 requires periodic risk assessments, not a one-time exercise. Stand up a risk register, score each item by likelihood and impact, schedule an annual review, and record each signed-off cycle so you can show the cadence to an assessor.
Run security awareness and phishing training (3.2.1, 3.2.2)
NIST 800-171 3.2.1 and 3.2.2 require role-based security-awareness training and records of completion. Roll out annual training and track who finished, then run simulated phishing campaigns and remediate the people who click. Readyline Pro includes the full LMS and phishing simulation so the training and the records live in one place.
A note on what "done" means
Configuring these settings hardens your Microsoft 365 GCC High tenant to the NIST 800-171 technical baseline. It is not a CMMC certification. A C3PAO assesses your documented System Security Plan, not your tenant directly, so the configuration above only counts once it is written down with evidence. Our free GCC High Setup Autopilot walks you through every step in order and hands the result to your control set when you move to Readyline Pro.
