Marine expeditionary unit A Marine Expeditionary Unit ( MEU , pronounced Myuu ) , formerly called " Marine Amphibious Unit " ( " MAU " ) , is the smallest Marine air - ground task force ( MAGTF ) in the United States Fleet Marine Force . Each MEU is an expeditionary quick reaction force , deployed and ready for immediate response to any crisis . A Marine Expeditionary Unit is normally built around the building blocks of a MAGTF : a reinforced Marine infantry battalion is the ground combat element , the aviation combat element is a composite helicopter squadron , a battalion - sized logistics combat element , and a command element . Troop strength is about 2 , 200 and usually commanded by a colonel , and is deployed from an amphibious assault ship . Currently a Marine expeditionary unit embarks Marines and equipment onto the amphibious warfare ships of an Expeditionary Strike Group ( ESG ) which also includes escort ships and submarines to protect them from air , surface , and submarine threats . For further protection and strong air support , such an ESG is often deployed along with one or more carrier battle group s . Attributes . The MEU is unique in that its air and ground combat elements are combined with a logistics combat element under one commander ; other services do not unite the command of air and ground forces until much higher command levels . When the United States Army integrates with Air Force assets , it typically is at the theater or corps level , with a general commanding , while at the division level it will integrate with Army aviation , which can be organized as organic at the battalion level . The MEU ' s ground combat element also combines artillery , light armor and tanks at a much lower level than was common in the Army until the development of the brigade combat team early in the War on Terror , with a similar concept , the combat command , being utilized in World War II . This air - ground task force concept is designed to thoroughly exploit the combat power inherent in air and ground assets by closely integrating them into a single force . The MEU brings all the supplies and logistical support it needs to sustain itself for quick mission accomplishment or to pave the way for any follow - up forces . This self - sustainment allows more flexibility in disposition and operations of forces , and allows the MEU to initiate operations sooner and let support catch up later , without having to wait for external logistical support to begin a mission . Deployments on U . S . Navy amphibious assault ships allows MEUs to seabase around the globe , ready for deployment at short notice . A typical MEU has approximately 2 , 200 Marines and sailors . It is equipped with : Many types of equipment are , or will soon , undergo a transitory phase as they are replaced . Some examples include the MV - 22 Osprey replacing the CH - 46 , the Marine Personnel Carrier replacing the LAV - 25 , the F - 35 Lightning II replacing the AV - 8B Harrier , the Ch - 53K Super Stallion replacing the CH - 53 , and the H - 1 upgrade program ( where the AH - 1Z Viper and UH - 1Y Venom replace the AH - 1W and UH - 1N ) . Elements . Ground Combat Element . The ground combat element ( GCE ) is based on the " battalion landing team " ( " BLT " ) , an infantry battalion reinforced with an artillery battery , amphibious assault vehicle platoon , combat engineer platoon , light armored reconnaissance company , tank platoon , reconnaissance platoon , and other units as the mission and circumstances require . The total strength is approximately 1 , 100 members . The reconnaissance platoon provides the basic element for the Maritime Special Purpose Force . This force consists of four elements . The assault platoon ( a direct action platoon augmented from Force Recon ) , security ( a selected infantry platoon from the battalion landing team ) , reconnaissance and surveillance assets , and a headquarters section . The total strength is approximately 350 Marines and sailors . Aviation Combat Element . The aviation combat element ( ACE ) is a Marine composite squadron ( reinforced ) composed of a medium or heavy helicopter squadron augmented with three other types of helicopters , one detachment of amphibious flight - deck - capable jets , and a Marine air control group detachment with air traffic control , direct air support , and anti - aircraft assets . Logistics Combat Element . The logistics combat element ( LCE ) ( formerly " combat service support element " or " CSSE " ) is based on the MEU combat logistics battalion ( CLB ) ( formerly " MEU service support group " or " MSSG " ) . It contains all the logistics specialists and equipment necessary for the MEU to support and sustain itself for up to 30 days in an austere expeditionary environment . It includes service support ( postal and disbursing ) , medical , dental , intermediate maintenance , intermediate supply ( consumables and secondary reparables ) , transportation ( distribution and landing support ) , explosive ordnance disposal , military police , utilities production and distribution , bulk fuels , internal communications , and various other technical experts . It consists of approximately 300 Marines and Sailors . Command Element . The command element ( CE ) , which includes the MEU commander and his supporting staff , provides command and control over the other three elements . It includes specialized detachments for naval gunfire , reconnaissance , surveillance , specialized communications , radio reconnaissance ( SIGINT ) , electronic warfare , intelligence and counterintelligence , and public affairs missions . The overall strength is about 200 Marines and sailors . Expeditionary Strike Group . Recently , MEUs have been deployed within an expeditionary strike group ( ESG ) in the Mediterranean , the Western Pacific , and periodically , the Atlantic and Indian Oceans . An ESG is typically composed of three amphibious ships that embark the necessary troops and equipment and are escorted by a guided missile cruiser ( CG ) and guided missile destroyer s ( DDG ) and submarine ( SSN ) support . Before the ESG , MEUs were typically deployed as part of an amphibious readiness group Amphibious ready group The MEU Cycle . MEUs maintain their subordinate elements in fifteen month cycles : a nine months stateside ( with six set aside for training ) , and a six month deployment aboard ship . These cycles ensure that at least two of the seven MEUs are deployed forward at any given time . Interim or buildup period : Upon completion of a deployment , the Marine expeditionary unit remains " special operations capable " for approximately one month , prepared to respond to events around the world . The MEU then releases its major subordinate elements ( MSEs ) , retaining only its command element . This period provides the command element a chance to rotate select personnel and begin planning for the addition of newly assigned MSEs and “ work - up ” training . When the MSEs are received , the MEU begins six months of intense pre - deployment training . Work - up period : Training during the six - month work - up period is often referred to as " crawl , walk , run " . The Marines and Sailors progress through curriculum and exercises that teach individual , small unit , and unit tactics while integrating the separate MEU elements into a cohesive , flexible , and powerful force . The work - up period includes training in many combat and noncombat skills , to include : Exercises conducted during the work - up period can include : Deployment : Following the work - up period , the MEU deploys for six months in support of geographic combatant commanders . During this time , the MEU is a forward - deployed , self - sustaining force that combatant commanders can direct to accomplish a variety of special operations and conventional missions . The missions may include : List of MEUs . West Coast MEUs . West Coast MEUs fall under I Marine Expeditionary Force , and their main area of operations includes the western Pacific and Indian oceans ( to include the Persian Gulf ) . East Coast MEUs . East Coast MEUs fall under II Marine Expeditionary Force and maintain presence in the Atlantic Ocean and Mediterranean Sea . Japan MEU . The 31st MEU is the only permanently forward - deployed MEU , maintaining a presence in the Pacific Ocean at all times as part of III Marine Expeditionary Force .