How to Secure Your Microsoft 365 for CMMC and Get the CMMC Badge/Seal

 

If your business contracts with the US Department of Defense, you need to comply with the Cybersecurity Maturity Model Certification (CMMC). Securing Microsoft 365 for CMMC is key, as it helps ensure sensitive federal information is properly protected. Here’s a detailed guide—explained simply—on how to secure your Microsoft 365 environment and how to get the CMMC badge/seal.

• Understand CMMC Requirements: CMMC is a standard created by the DoD for contractors, focusing on protecting Controlled Unclassified Information (CUI) and Federal Contract Information (FCI). CMMC has different levels (1–3), each with specific security practices like access control, incident response, and data encryption. Know your required CMMC level based on your contract needs.
• Choose the Right Microsoft 365 Plan: Only certain Microsoft 365 plans are designed for CMMC—like Microsoft 365 Government G3/G5 or Commercial M365 E5 (with some extra controls). These offer advanced security, compliance, and data retention capabilities.
• Configure Access Controls: Use Multi-Factor Authentication (MFA) for ALL users, enforce strong passwords, enable Conditional Access Policies, and control guest access. This prevents unauthorized access and is a key CMMC requirement.
• Apply Data Protection/Encryption: Microsoft 365 offers Data Loss Prevention (DLP), Microsoft Information Protection, and built-in encryption (like BitLocker and Azure Rights Management). Set up DLP rules to prevent accidental sharing of CUI/FCI, and use encryption for data at rest and in transit.
• Configure Audit Logs: Enable Unified Audit Log and Retain Logs for at least 90 days (more for Level 2/3). This is crucial for monitoring, investigations, and passing a CMMC audit.
• Enable Threat Protection: Activate Microsoft Defender for Office 365 and anti-phishing, anti-malware, and anti-spam policies to protect against common cyber threats.
• Manage Devices: Use Intune or Endpoint Manager for mobile device and computer compliance. Require encryption on user devices and enforce security baselines.
• User Training: Educate staff regularly about phishing, data handling, and CMMC policies. Security awareness is a big part of passing the CMMC audit.
• Review and Document Policies: CMMC auditors want to see clear, documented security policies and procedures—this includes user onboarding/offboarding, data classification, and incident response plans. Keep everything up to date.
• Perform a Readiness Assessment: Before your official CMMC audit, get a gap assessment. A consulting firm like OCD Tech can evaluate your Microsoft 365 environment, review your settings, and help you remediate weaknesses. This makes your official audit go much smoother.

How to get the CMMC Badge/Seal:

• After configuring your Microsoft 365 for CMMC, reach out to a CMMC Third-Party Assessor Organization (C3PAO) for an official assessment.
• The assessor will review technical controls and documentation, and interview staff to ensure practices are followed.
• If you meet CMMC standards, you receive the CMMC certificate or badge for your level, valid for 3 years.
• Teams like OCD Tech can guide you through readiness, documentation, and remediation, helping ensure your first audit is successful.

Most Important for Passing the Audit:

• All technical controls must be correctly configured (e.g., MFA, DLP, encryption).
• You must have detailed, current documentation of all policies and procedures.
• Staff must actually follow policies—auditors check this!
• Your logs and evidence must be accessible and retained long enough for auditor review.

Pro Tip: A partner like OCD Tech specializes in Microsoft 365 security, CMMC readiness, and audit prep, making it much easier to achieve and keep your CMMC compliance.