Exostar Managed Microsoft 365 is a fully managed Microsoft 365 GCC High environment designed for defense contractors and organizations in the Defense Industrial Base (DIB) that need to store, share, and collaborate on Controlled Unclassified Information (CUI) in compliance with CMMC 2.0 and NIST SP 800-171 requirements. The solution is deployed as a secure enclave that isolates sensitive data and enforces strict identity and access controls, ensuring only authorized users can access or share CUI. It provides built-in support for 85 of the 110 NIST SP 800-171 controls, reducing the compliance gap for organizations pursuing CMMC Level 2 certification. Access to the environment is managed through Exostar's Managed Access Gateway (MAG), which serves as the identity and access management entry point for users within the Exostar network. External partners can submit CUI into the secure enclave via a Compliant File Drop feature — without requiring full user provisioning — while maintaining logging and encryption for audit readiness. The solution is offered as a subscription-based managed service, meaning deployment, configuration, updates, and compliance monitoring are handled by Exostar rather than the subscribing organization. It is scalable to accommodate varying user counts, storage needs, and compliance complexity. The platform supports compliance with DFARS, ITAR, EAR, and other regulations relevant to the DIB. It also provides assessment-ready documentation to support CMMC self-assessments and third-party audits. The solution is available for both small-to-medium businesses (SMB) and enterprise customers, and it is a core component of Exostar's broader CMMC Ready Suite.