Under the contract with the Defense Information Systems Agency (DISA), Microsoft will provide consulting services that include software developers and product teams "to leverage a variety of proprietary resources and source code" and Microsoft premier support services, such as tools and knowledge bases, problem resolution assistance from product developers.

The DoD also said the deal would include "access to Microsoft source code when applicable to support Department of Defense's mission".

The support will mostly take place in the US, but the DoD said support services may also be required at multiple locations outside the continental US.

In January 2016, the DoD announced plans to migrate four million devices to Windows 10 by January 2017, although rollout in some military organizations may take a year longer. The DoD said the move would improve its "cybersecurity posture, lower the cost of IT and streamline the IT operating environment".

DISA is a combat support agency of DoD with 6,000 civilian employees, 1,500 active duty military personnel from the Army, Air Force, Navy, and Marine Corps, and approximately 7,500 defense contractors. The agency provides and operates command and control and enterprise information systems.

Microsoft and DISA have not responded to a request for comment at the time of publication.