Buying GCC High Won’t Make You CMMC Compliant

Purchasing Microsoft GCC High licenses is not a compliance strategy. Plenty of defense contractors have migrated their entire organization into GCC High, burned through their budget, and ended up no closer to passing a CMMC Level 2 assessment. The platform is a tool. What you do with it determines whether it’s money well spent.

Scope Before You Spend

The first mistake contractors make is buying licenses before they know what they’re protecting. Before you migrate a single user or a single byte of data, you need to know exactly where your CUI lives and who actually needs to touch it.

That answer drives everything. A properly scoped CUI enclave means fewer licenses, a smaller attack surface, and a tighter assessment scope. Skipping this step means you’re paying for coverage you don’t need and creating exposure you didn’t account for.

Lock Down Admin First

Once your boundary is defined, the first technical task isn’t onboarding users, it’s securing your administrative layer.

That means dedicated admin accounts, MFA enforced for every privileged role, and isolated break-glass accounts configured and documented. Get this right before anything else touches the environment. It directly addresses your AC and IA domain requirements and gives you concrete evidence to show an assessor.

Conditional Access Is Non-Negotiable

With your admin accounts secured, Conditional Access policies go in next. MFA on every login, legacy authentication blocked, and device compliance enforced. Only managed, compliant devices get in. (Pro Tip: Want to constrict your boundary even further? Go the SaaS route and use W365 endpoints if you only handle digital CUI and don’t store it on prem)

This isn’t optional configuration. It satisfies IA.L2-3.5.3 and closes off the most common attack paths into your environment. Skipping or softening these policies is a finding waiting to happen. Plus, if you go ahead and set up MFA from the start, you can figure out earlier if it’s misconfigured from the start before you try to onboard 20 users and then turn it on.

Onboard Users Last

Only after your boundary, identity layer, and access policies are locked down do you start moving users into the enclave. Every user gets enrolled in MFA, assigned the right license, and lands in an environment already governed by your security baseline.

A controlled rollout also gives you something valuable at assessment time: documented evidence that you manage user provisioning deliberately. That directly supports your CM and AU practices. (Another Pro Tip: AC.L2-3.1.1 – Don’t just use Entra ID or Active Directory as your “source of truth” for whom the authorized users are. Those users ALREADY have access, the control is asking who has been identified to have access. Use a separate “approved” list (either your time keeping software, or an HR list) that you can vet against the actual Entra/AD list)

What This Actually Gets You

Done in this order, GCC High stops being a line item on an IT invoice and becomes a defensible compliance foundation. You still need written policies, an incident response plan, and security awareness training, and more in order achieve Level 2, but this technical buildout provides a good portion of your technical controls and prevents the costly remediation that comes from standing up the environment wrong the first time.

Your prime contractors want to see that you can protect CUI, but they also don’t expect you to scope your entire company and you can’t just buy GCCH and call it a day.

Not sure where your CUI boundary actually starts? That’s usually the right place to begin. Contact us and we’ll work through it.