Ground combat element

These organizations contain a headquarters unit that provides command and control (management and planning for manpower, intelligence, operations and training, and logistics functions) as well as scout/sniper, aviation liaison/forward air controller, nuclear/biological/chemical defense, communications, service (supply, motor transport, weapons maintenance, and dining facility), and Navy combat medical and chaplain's corps personnel.

In addition, all Marine infantry units are prepared, and regularly train, to perform heliborne, or "vertical envelopment" (i.e., air assault) operations when supported by MV-22 medium tiltrotor and/or CH-53 heavy helicopters and mechanized operations (when supported by attached amphibious assault vehicle units).

Additionally, some Marine infantrymen (usually only those assigned to reconnaissance or special operations units) attend U.S. Army Airborne or Ranger training.

However, since the USMC does not maintain either airborne or Ranger infantry units, only a relatively small number of Marines ever attend these two schools.

Generally, MEF postings are permanent, while MEBs and MEUs rotate their GCE, ACE, and LCE twice annually.