If you're already operating in Microsoft 365 GCC, you might assume you're in the clear when it comes to compliance. But for many government contractors handling Controlled Unclassified Information (CUI) or working with the Department of Defense (DoD), GCC may not go far enough. That’s where GCC High comes in.
Here's why organizations are upgrading—and how GCC High migration services can help you make the move smoothly.
1. Understand the Difference: GCC vs. GCC High
Both environments are built for U.S. government use, but the compliance boundaries and data handling capabilities vary significantly.
| Feature | GCC | GCC High |
|---|---|---|
| Data Residency | U.S. only | U.S. only |
| Admin Access | Global Microsoft staff | U.S. citizens only |
| ITAR Support | ❌ Not guaranteed | ✅ Fully supported |
| DoD SRG IL4/IL5 Capability | ❌ No | ✅ Yes |
| CUI Compliance | Partial | Full support |
If your compliance obligations require FedRAMP High, ITAR, or DoD SRG IL4/IL5 alignment, GCC High is the required path.
2. You're Preparing for CMMC Level 2 or Above
CMMC 2.0 introduces clearer distinctions between controlled and uncontrolled environments. For Level 2 and Level 3, operating in GCC may not meet the criteria for secure handling of CUI.
By working with GCC High migration services, you ensure your environment is aligned with the specific hosting requirements auditors will expect.
3. GCC High Provides Additional Security Isolation
GCC High is hosted in a dedicated infrastructure that’s physically and logically separated from commercial and even standard GCC tenants. This isolation is essential for contractors working on sensitive or classified projects and offers:
Enhanced audit logging
Tighter identity and access control
U.S.-only administrative oversight
4. Certain Contracts Now Require It
Whether it's a new RFP or an updated flow-down clause from a prime contractor, GCC High is increasingly being mandated. If you're starting to see contract language that specifies GCC High, it's time to plan the transition.
5. Migration Takes Time—Start Now
Upgrading from GCC to GCC High isn't instant. It involves:
New tenant provisioning
Licensing verification
Data and identity migration
Workflow reconfiguration and revalidation
Starting early allows you to avoid business disruption, compliance pressure, and last-minute errors.