Direct commission officer

A direct commission officer (DCO) is a United States uniformed officer who has received a commission without the typical prerequisites for achieving a commission, such as 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.

Civilians who have special skills that are critical to sustaining military operations, supporting troops, health and scientific study may receive what are called "direct commissions." These officers usually occupy leadership positions in the following areas: law, science, medicine, pharmacy, dentistry, nurse corps, intelligence, supply-logistics-transportation, engineering, public affairs, chaplain corps, oceanography, merchant marine affairs, and others.

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 two U.S. armed services.

The U.S. Marine Corps does not offer a DCO program. The Marines, however, do have a substantial population of "Mustang" officers, who are commissioned officers who have served as enlisted personnel before earning their commissions. The Marines also have a robust chief warrant officer (CWO) and limited duty officer (LDO) program. CWOs can attain the rank of LDO captain and can not rise higher than lieutenant colonel. CWOs and LDOs are utilized as experts within their occupational field only.

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