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 typically slightly over 3 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 which are commissioned officers who have served as enlisted before earning their commission . 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 . The U . S . Public Health Service Commissioned Corps and the National Oceanic and Atmospheric Administration Commissioned Corps exclusively use a DCO program to commission their officers . Depending on the specialization and duty - status of the officer , " DCOs " as they ' re called , will attend either Officer Indoctrination School ( OIS ) , Officer Development School ( ODS ) , or Direct Commission Officer School ( DCO School ) which vary from two weeks duration for certain Reserve DCOs to five weeks duration for Active Duty DCOs . U . S . Army Reserve Direct Commission Officers . The United States Army Reserve uses the DCO program to bring specialized skills and backgrounds , and to fill critical shortages in the Army Reserve commissioned officer corps . A majority of the people obtaining direct commissions in the Army Reserve are prior - enlisted personnel . However , there have been instances when qualified civilians were directly commissioned as well . The general requirements for a direct commission in the Army Reserve are : 60 semester hours of college credit ; the ability to get and maintain a " secret " clearance ; be physically qualified ( obtain and pass a medical evaluation ) ; an open slot or " billet " in an Army Reserve unit ; three recommendation letters from commissioned field - grade officers ; and a recommendation from a direct commissioning board . Once selected , the applicant signs the oath and is sworn in by another commissioned officer . At that point the newly commissioned officer will then need to attend the Basic Officer Leadership Course ( BOLC ) in their assigned area of concentration ( AOC ) before becoming fully qualified . Direct commission officers in the Army Reserve can serve in the same specialities and hold billets as ROTC , OCS , and USMA graduates . Direct commission officers may be promoted to flag officer rank and hold command within their specialty of work . U . S . Navy Direct Commission Officers . The United States Navy has an extensive DCO program . It is important to distinguish between the Navy ' s active duty component staff corps school , called Officer Development School ( ODS ) , and the Navy ' s reserve component Direct Commission Officer School ( DCO School ) . Base Realignment and Closure ( BRAC ) of 2005 decreed that reserve officer DCO School be re - located to Newport , Rhode Island from its current location at Naval Air Station Pensacola , Florida as of January 2007 . The U . S . Navy is consolidating many of its schools in one central location - - Naval Station Newport , RI . The Navy is currently considering merging DCO School , Limited Duty Officer School , and Mustang University into one contiguous officer training program — all located in Newport , RI . As of January 2007 all Navy Reserve DCO , LDO and CWO Officers attend the same two week course of instruction in Newport . Active duty ODS , a five week course , is also located in Newport , RI , as well as Officer Candidate School ( OCS ) , the twelve week program that college graduates wishing to join the US Navy as active duty officers go through . The U . S . Navy Reserve Direct Commissioning Program allows university - educated professionals , between ages 19 to 35 ( or older , in some cases ) , the opportunity to be appointed as an officer in the Navy Reserve . Most DCOs hold advanced degrees ( MAs , MBAs , JDs , MDs , DOs , PharmDs and Ph . Ds . ) and / or significant civilian work experience . In recent years , the number of direct commissions offered by the Navy Reserve has increased due to the need for skilled officers to serve as Individual Augmentees ( IAs ) in Iraq and Afghanistan . The Direct Commissioning Program serves the expanded needs of the Navy in certain officer skill areas listed below in alphabetical order by category : Unrestricted Line Officer Restricted Line Officer ( including Special Duty Officer ) Staff Corps Officer Limited Duty Officer ( Various specialties ) Warrant Officer ( Various specialties ) Some skill areas may not have openings each year . Each year , skill area recruiting quotas are promulgated for recruiters to fill . Upon completion of their training regimen , DCOs serve on nearly every type of ship in the fleet and at shore establishments around the globe . Navy DCOs are forward deployed and are currently serving on the ground in Iraq and Afghanistan . They are an integral part of the Navy ' s role in the War on Terror . U . S . Coast Guard Direct Commission Officers . The United States Coast Guard uses the DCO program to bring specialized skills and backgrounds into the Coast Guard commissioned officer corps . The DCO course is conducted by the Officer Candidate School , located at the United States Coast Guard Academy in New London , Connecticut . Depending on program and background , the course is three , four , or five weeks long . For the five - week program , the first week is an Indoctrination week . There are seven Direct Commission Officer programs : Some DCO programs may not have openings each year . While DCOs are expected to fill specific specialty areas , they are not specifically precluded from crossing into other operational or support billets in follow - on assignments . U . S . Public Health Service ( Commissioned Corps ) Direct Commission Officers . The PHSCC Direct Commissioning Program allows university - educated professionals , between ages 19 to 45 ( or older , in some cases ) , the opportunity to be appointed as an officer in the Public Health Service Commissioned Corps . Most PHSCC DCOs hold advanced degrees ( DDSs , DMDs , MSs , MDs , DOs , PharmDs and Ph . Ds . ) and significant civilian work experience , and the minimum in many programs is a master ' s degree from a duly accredited program . One of the fields requiring only a baccalaureate degree is engineering . The Direct Commissioning Program serves the expanded needs of the PHS in certain officer skill areas listed below : National Oceanic and Atmospheric Administration ( Commissioned Corps ) Direct Commission Officers . The NOAA Corps Direct Commissioning Program allows university - educated professionals , between ages 19 to 35 ( or older , in some cases ) , the opportunity to be appointed as an officer in the National Oceanic and Atmospheric Administration Commissioned Corps . Many NOAA Corps DCOs hold advanced degrees ( MS , MAs and Ph . Ds . ) and significant civilian work experience , though the minimum requirement is a baccalaureate degree . The Direct Commissioning Program serves the expanded needs of the NOAA Corps in certain officer skill areas listed below :