A direct commission officer (DCO) is a United States uniformed officer who has received an appointed commission without the typical prerequisites for achieving a commission, such as attending a four-year service academy, a four-year or two-year college ROTC program, or one of the officer candidate school or officer training school programs, the latter OCS/OTS programs typically slightly over three months in length. The U.S. Navy, U.S. Air Force and U.S. Coast Guard have more extensive active and reserve component DCO programs than the other three U.S. armed services.