If you’re here, you’ve probably just been told some version of this:

“You need GCC High for CMMC.”

Maybe it came from a consultant. Maybe from a prime. Maybe from another contractor who already migrated. Then you saw the licensing cost and realized the migration itself may cost even more. Now you’re trying to figure out whether that move is actually required.

Microsoft GCC High is a common path to CMMC Level 2 compliance, but it's not a regulatory requirement. The real requirement is that you meet the 110 controls in NIST SP 800-171 and, if you store or process CUI in the cloud, that your cloud service meets FedRAMP Moderate equivalency under DFARS 252.204-7012.

GCC High satisfies those expectations cleanly — but it's not the only architecture that can.

This guide walks through what GCC High actually solves, how to think about the decision, and five viable alternatives, including when each one makes sense.

What GCC High solves

GCC High exists to support organizations handling sensitive government data, including export-controlled ITAR and EAR information. It runs on Azure Government infrastructure, enforces U.S.-person-only access controls, and aligns well with higher impact levels like IL4 and IL5.

It is also widely adopted in the defense ecosystem. Assessors are familiar with it. Primes are comfortable with it. That familiarity reduces friction.

What it does not do is make you CMMC compliant on its own. You still must implement, document, and produce evidence for NIST SP 800-171 controls. GCC High provides a compliant infrastructure foundation. It does not replace governance.

That distinction matters because many contractors migrate for the perception of safety rather than because their contracts require export-controlled handling or IL5 infrastructure.

The real cost of a full GCC High migration

The licensing delta gets attention, but the larger cost is operational.

A full migration often means rebuilding your tenant, reconfiguring identity and device management, migrating email and SharePoint, validating integrations, retraining staff, and rewriting documentation. For mid-sized contractors, this process commonly takes three to nine months. Internal labor, consulting fees, and workflow disruption frequently outweigh the licensing premium itself.

For some organizations, that investment is justified. For others, it is unnecessary scope expansion.

Before evaluating alternatives, it helps to apply a decision framework.

How to decide before you migrate

Before evaluating vendors, zoom out.

The first variable that matters is scope. If only a fraction of your workforce ever touches CUI, migrating your entire tenant may increase cost and assessment complexity without improving your actual compliance posture. If most employees interact with CUI daily, a broader architectural move may make operational sense.

Export control is the next gating factor. Handling ITAR or EAR data narrows your options immediately because U.S.-person-only access and stronger segregation controls become mandatory. If export control does not apply, the architectural field widens considerably.

Timeline also reshapes the decision. Some environments deploy in days. Others require quarters. If certification pressure is near-term, a multi-month rebuild may create more risk than it removes.

Internal maturity matters as well. Certain platforms are closer to turnkey in the defense ecosystem. Others require careful configuration and documentation discipline to stand up defensibly. The right choice is the one your organization can implement cleanly, not just theoretically.

Option 1: Microsoft 365 GCC (FedRAMP Moderate)

Microsoft 365 GCC sits between commercial M365 and GCC High. It runs on Azure Commercial infrastructure but meets FedRAMP Moderate requirements, satisfying the baseline DFARS cloud obligation for most non-export-controlled CUI.

For Microsoft-centric organizations that do not handle ITAR or EAR data, GCC often provides the most cost-efficient path that still aligns cleanly with DFARS expectations. Feature parity is strong, migration is comparatively straightforward, and user disruption is minimal.

Where it falls short is export control and higher impact levels. GCC does not enforce U.S.-person-only access, nor does it operate on physically segregated government infrastructure. If your contracts later expand into export-controlled work, you may face a second migration.

GCC works best when your CUI is not export-controlled and your goal is to meet baseline federal cloud requirements without absorbing unnecessary infrastructure cost.

Option 2: Encrypted overlays (PreVeil, Virtru)

Encrypted overlays take a containment approach rather than a replacement approach.

Instead of rebuilding your productivity environment, these platforms add a secure, FedRAMP-authorized channel for CUI email and file handling on top of your existing Microsoft 365 tenant. Users continue operating in commercial M365 for most activity while routing CUI communications through an encrypted layer.

The primary advantage is speed and cost control. Deployment can happen quickly, and only CUI-accessing users require licenses. There is no tenant rebuild, no large-scale migration, and far less user disruption.

The tradeoff is architectural separation. These platforms protect CUI communications but do not replace your broader collaboration environment. Certain NIST SP 800-171 controls must still be implemented outside the overlay, and documentation must clearly explain how the two environments coexist.

For organizations where CUI represents a defined subset of operations, overlays often provide the fastest path to defensible compliance without overhauling the entire IT stack.

Option 3: Google Workspace with assured controls

Google Workspace, when configured with Assured Controls or Assured Workloads, can support CUI handling within a FedRAMP-authorized cloud environment.

For organizations already operating on Google, this avoids a disruptive platform change and preserves existing workflows. Google Cloud has achieved CMMC Level 2 certification, which strengthens platform credibility in federal contexts.

The difference is implementation burden. Google environments are not CMMC-ready by default. Controls must be configured precisely, and documentation mapping to NIST 800-171 requires careful attention. Assessors evaluate configuration and evidence, not which vendor you're running.

This path works well for technically mature teams that already live in Google’s ecosystem and are comfortable owning the configuration narrative during assessment.

Option 4: AWS GovCloud

AWS GovCloud provides FedRAMP High infrastructure and supports ITAR and EAR workloads. It is particularly useful for contractors building custom applications, secure development environments, or government-facing databases.

It is not a productivity suite replacement. Email, collaboration, and document management require additional tools layered on top.

GovCloud makes sense when your compliance architecture revolves around infrastructure and application hosting rather than user-facing collaboration tools. In most cases, it is paired with another platform for end-user productivity.

Option 5: The CUI enclave strategy

Rather than asking which cloud to migrate to, many contractors benefit from asking a different question: why migrate everyone?

An enclave isolates CUI handling to a clearly defined boundary. Only the users, systems, and applications that process CUI sit inside that environment. The rest of the organization remains on commercial infrastructure.

This approach frequently changes the economics of compliance. Licensing exposure shrinks. Assessment scope narrows. Documentation complexity decreases. Migration disruption is limited to the portion of the organization that truly requires higher controls.

It is not a workaround. Enclaves are widely accepted by C3PAOs and align with DoD-supported models like the Army’s NCODE pilot. The requirement is clarity. The CUI boundary must be well defined, enforced, and documented.

For contractors where DoD work is part of the business and not the entirety of it, the enclave strategy is often the most rational starting point. Only after defining that boundary does it make sense to decide whether the enclave itself should run on GCC High, GCC, or an encrypted overlay.

The right architecture is the one that fits your scope

GCC High is a strong solution, but it isn't automatically the right solution.

The architecture that makes sense for your organization depends on how much CUI you handle, whether export control applies, how quickly you must certify, and how much migration complexity you can absorb without disrupting operations.

Overbuying infrastructure doesn't strengthen CMMC compliance. Underscoping your boundary does increase assessment risk. The decision should reflect contract obligations and operational reality, not peer pressure.

Secureframe Defense helps organizations implement the architecture that fits their operational and compliance needs. The platform can automatically provision compliant cloud environments, support GCC High deployments, isolate CUI into secure enclaves, and continuously monitor NIST 800-171 and CMMC controls across Microsoft, Google, and AWS environments.

Secureframe Defense also maps your live configuration and documentation directly to the NIST 800-171 controls, so you can see whether your chosen architecture is defensible before a C3PAO ever steps in.

If you're weighing a GCC High migration against alternatives, schedule a call with one of our product experts to assess the compliance impact of your current environment before committing to a full rebuild.