I think this might be the US Military Merit medal: Product : USA - Commendation Medal - Army Military Merit : from the myCollectors Website
It is indeed a US commendation medal. It could either be an Army Commendation Medal or a Navy and Marine Corps Commendation Medal; the obverse design is essentially identical. I don't know if the reverse of the two types are the same or different. You can normally tell them apart due to the different ribbon designs used by the Army and Navy.