By Payam Pourkhomami, President & CEO of OSIbeyond
The Department of Defense’s Cybersecurity Maturity Model Certification program has fundamentally transformed the compliance landscape for defense contractors. With the Final Rule taking effect December 16, 2024, and mandatory third-party assessments beginning in 2025, the approximately 100,000 companies across the defense industrial base need to achieve and maintain CMMC compliance without undermining their operational efficiency or breaking their budgets.
Microsoft’s Government Community Cloud High, a.k.a. GCC High, has emerged as the premier solution for achieving CMMC compliance, offering a FedRAMP-authorized platform that can support the vast majority of technical security controls required by NIST SP 800-171. But here’s the key question every defense contractor must answer: should you migrate your entire organization to GCC High, or implement it as a targeted enclave for just your CUI-handling operations?
The Full Migration Path: Bringing Your Entire Organization into GCC High
Aspect | What It Means for Your Organization |
|---|---|
| Who Gets GCC High | Every employee from CEO to newest intern receives a GCC High account. |
| Migration Process | Complete rebuild of IT infrastructure (all accounts, sites and policies recreated from scratch). |
| Timeline | Several months including licensing, provisioning, data migration, and parallel operations. |
| Data Transfer | Phased migration of email, files and collaboration tools to GCC tenant |
| User Impact | Employees must adjust to restricted external sharing and limited third-party app availability. |
| End Result | Entire organization operates in isolated government cloud with federal compliance standards. |
When we talk about full migration to Microsoft GCC High, we’re describing a complete organizational transformation where every user, system and workflow transitions from Office 365 commercial IT infrastructure to Microsoft’s government cloud environment.
The full migration approach means that every employee (from the CEO to the newest intern) receives a GCC High account. Staff with access to CUI and staff without access share the same platform. Similarly, all email communications, file storage, collaboration tools and business applications operate within this secured, isolated environment that meets federal compliance standards.
If you’re already a Microsoft 365 commercial user, the migration to GCC High requires completely rebuilding your tenant because your existing Microsoft 365 environment and the GCC High environment are fundamentally incompatible. They exist in separate, isolated clouds that cannot directly communicate or transfer settings. As such, every user account must be recreated, every SharePoint site rebuilt, every Teams channel reestablished and every security policy reconfigured in the new government cloud environment.
The migration process itself typically unfolds over several months, beginning with obtaining GCC High licensing through an authorized Microsoft partner. Microsoft then manually provisions the new GCC High tenant in the government cloud, a process that can take several weeks. During this time, your organization should map out exactly how your current environment will translate to the new platform and identify which third-party applications have government cloud versions available and which workflows will need to be redesigned.
Data migration requires careful orchestration and often runs in phases. Email typically moves first, using tools like Microsoft’s Exchange migration services or third-party solutions that support government cloud endpoints. File migrations follow, with SharePoint and OneDrive content transferred through specialized migration tools configured for the .us domains. Throughout this process, most organizations run parallel environments for several weeks or months.
The parallel operation allows for gradual transition and troubleshooting without complete business disruption. It also gives employees accustomed to freely sharing files with external partners, using consumer apps integrated with their work accounts or accessing their email from any device anywhere time to adjust to a more controlled environment.
The Enclave Strategy: Creating a Secure GCC High Boundary for Limited CUI Exposure
Aspect | What It Means for Your Organization |
|---|---|
| Who Gets GCC High | Only CUI-handling employees (e.g., 38 users in a 150-person company) |
| Dual Operations | Enclave users maintain two accounts (commercial for regular work, GCC High for DOD projects) |
| Boundary Management | Robust controls prevent CUI from leaving enclave (DLP policies, access restrictions, dedicated devices) |
| Decision Points | Determine which peripheral users (legal, finance, IT) need enclave access vs. temporary procedures |
| Training Focus | Enclave users must understand when to use which environment and consequences of boundary violations |
| Commercial Operations | Majority of employees continue unchanged with existing tools and workflows |
In contrast to full migration, the enclave approach creates a segregated GCC High environment specifically for your CUI-handling operations and employees while maintaining your existing commercial IT infrastructure for everything else. It’s like building a highly secure vault within your existing office building.
Let’s say that your company is a 150-person engineering firm where 30 engineers work on DOD contracts while the remaining 120 employees focus on commercial aerospace, automotive and consumer electronics projects. In this scenario, only those 30 engineers, plus perhaps five executives who oversee defense contracts and three contracts administrators who manage DOD paperwork, would need GCC High accounts. That’s 38 users in the enclave versus 150 users if you did a full migration.
You might discover that while only 30 engineers directly work on defense projects, your legal team occasionally reviews DOD contracts containing CUI, your CFO needs visibility into defense project financials and your IT security team must monitor the enclave environment. Each of these touchpoints requires a decision: do you bring these peripheral users into the enclave, establish controlled procedures for temporary access or restructure workflows to eliminate their need to touch CUI?
The technical implementation involves provisioning a separate GCC High tenant with licenses only for your identified CUI users. These enclave users essentially operate in two digital worlds. They might start their morning checking emails in their commercial Office 365 account for updates on civilian projects, then switch to their GCC High account to review specifications for a military component design.
The boundary between these environments requires robust protection. Your organization needs to implement technical controls to prevent CUI from accidentally leaving the enclave: data loss prevention policies that block external forwarding of emails from GCC High accounts, conditional access rules that prevent downloads to unmanaged devices and likely separate workstations or virtual desktops dedicated solely to enclave access.
Training becomes absolutely paramount with this model. Your enclave users must clearly understand that, for example, accidentally forwarding a DOD specification to their commercial email account or saving a military design file to their regular OneDrive could trigger a reportable security incident. They need to recognize which conversations involve CUI, remember to schedule DOD project meetings using their GCC High calendar (not their commercial calendar) and resist the natural impulse to consolidate everything into one system for convenience.
Making the Decision: When to Choose Full Migration vs. Enclave
Factor | Full GCC High Migration | GCC High Enclave |
|---|---|---|
| Best For | DOD contracts are majority of revenue | DOD contracts are minority of revenue |
| Licensing Costs | Higher (all employees need GCC High) | Lower (only CUI users need GCC High) |
| IT Complexity | Simple (one environment to manage) | Complex (dual environments to maintain) |
| User Experience | Seamless just as it would be in a commercial environment | Complicated and limited workflow capability (such as a VDI or dedicated device) |
The choice between full GCC High migration and an enclave approach ultimately comes down to what proportion of your business involves DOD contracts.
When DOD Work Drives Your Business
If DOD contracts represent the majority of your revenue, then full migration to GCC High typically makes more strategic and financial sense. When most of your business involves defense work, attempting to maintain separate environments becomes an exercise in swimming against the current.
Typically, you’ll find that more employees need CUI access than initially anticipated, collaborative workflows constantly cross boundaries and the overhead of managing dual systems outweighs any savings from reduced licensing. By the time you map all CUI touchpoints, you’ve brought most of your organization into the enclave anyway—but with all the complexity of maintaining two systems.
When Commercial Work Predominates
Conversely, when DOD contracts represent only a relatively small portion of your revenue, the enclave strategy becomes compelling. Forcing your entire organization into GCC High would be like requiring everyone to wear body armor because some employees work in a secure area. The commercial majority of your business would gain nothing from the enhanced security controls, but it would certainly experience the full burden of operational restrictions and increased costs.
For these organizations, a well-designed enclave contains costs while maintaining full CMMC compliance for defense work. Your commercial teams continue using familiar tools and workflows, external collaboration remains seamless for non-DoD projects, and you only pay premium GCC High licensing for users who actually handle CUI.
Conclusion
Your decision as to how to implement GCC High should align with your business reality: if defense contracts drive the majority of your revenue, full migration eliminates the complexity and risk of managing dual environments while providing uniform security across your organization. If DOD work represents a smaller portion of your business, an enclave strategy preserves operational flexibility for your commercial operations while containing compliance costs to just those users who actually handle CUI.
Whether you choose full migration or an enclave, Microsoft GCC High provides the compliant foundation necessary to maintain your position in the defense industrial base, and we at OSIbeyond can help you assess which approach best fits your organization’s unique needs and guide you through implementation to achieve CMMC compliance efficiently.
