For those unaware: Office 365 GCC uses Entra Public/Commercial. (Formerly known as Azure AD Public) This includes all other Government Community Cloud (GCC) products & services including, Dynamics 365 GCC, Power Platform GCC, Microsoft 365 Copilot GCC, etc.
For an explanation of this, please review the following:
Why does Office 365 GCC use Microsoft Entra Public?
The first Office 365 US Government environment, Government Community Cloud (GCC), was created when Microsoft had a single cloud directory. The Office 365 GCC environment was designed to use Microsoft Entra Public while still adhering to controls and requirements outlined in FedRAMP Moderate, Criminal Justice Information Services (CJIS), Internal Revenue Service (IRS) 1075, and National Institute of Standards and Technology (NIST) Special Publication (SP) 800-171. Azure Government, with its Microsoft Entra infrastructure, was created later. By that time, GCC had already secured the necessary compliance authorizations (for example, FedRAMP Moderate and CJIS) to meet Federal, State, and Local government requirements while serving hundreds of thousands of customers. Now, many Office 365 GCC customers have two Microsoft Entra tenants:
- one from the Microsoft Entra subscription that supports Office 365 GCC
- and the other from their Azure Government subscription,
with identities in both.
Read more here:
- DOCS: Planning identity for Azure Government applications
https://docs.microsoft.com/en-us/azure/azure-government/documentation-government-plan-identity#frequently-asked-questions
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