Colonial Military Authority
From Halopedia, the Halo wiki
The Colonial Military Administration is the organization that commands all forces of the UNSC. It is apparently above HIGHCOM. They personally ordered Project: ORION to take place, as well as the creation of the Spartan supersoldiers.
NOTE: The Colonial Military Administration has only been mentioned once, its functions are unclear. But it is likely under the auspecies of the Colonial Administration Authority.
