The United States Army uses various personnel management systems to classify soldiers in different specialties which they receive specialized and formal training on once they have successfully completed Basic Combat Training (BCT).
Enlisted soldiers are categorized by their assigned job called a Military Occupational Specialty (MOS). MOS are labeled with a short alphanumerical code called a military occupational core specialty code (MOSC), which consists of a two-digit number appended by a Latin letter. Related MOSs are grouped together by Career Management Fields (CMF). For example, an enlisted soldier with MOSC 11B works as an infantryman (his MOS), and is part of CMF 11 (the CMF for infantry).
Commissioned officers are classified by their area of concentration, or AOC. Just like enlisted MOSCs, AOCs are two digits plus a letter. Related AOCs are grouped together by specific branch of the Army or by broader in scope functional areas (FA). Typically, an officer will start in an AOC of a specific branch and move up to an FA AOC.
Warrant officers are classified by warrant officer military occupational specialty, or WOMOS. Codes consists of three digits plus a letter. Related WOMOS are grouped together by Army branch.
The Army is currently restructuring its personnel management systems, as of 2019. Changes took place in 2004 and continued into 2013. Changes include deleting obsolete jobs, merging redundant jobs, and using common numbers for both enlisted CMFs and officer AOCs (e.g. "35" is military intelligence for both officers and enlisted).
Immaterial & Personnel Special Reporting Codes
Officer
00A Duties Unassigned
00B General Officer
00C Relieved from Duty; Sick in Hospital or Quarters
00D Newly Commissioned Officers Awaiting Entry on Active Duty for Officer Basic Course Attendance 00E Student Officer 01A Officer Generalist 01B Aviation/Infantry/Armor/MI Immaterial 01C Chemical/Engineer/MP Immaterial 01D Army Financial Management/Adjutant General immaterial 02A Combat Arms Generalist 02B Infantry/Armor Immaterial 02C Infantry/Armor/Field Artillery/Engineer Immaterial 03A Infantry/Armor Immaterial 05A Army Medical Department 09G Army National Guard (ARNG) on Active Duty Medical Hold 09H US Army Reserve (USAR) on Active Duty Medical Hold
Warrant
001A Unqual in Auth WO MOS
002A Patient
003A Student
004A Duties Unassigned
011A Brch/MOS Immaterial
019G Army National Guard on Active Duty Medical Hold
019H US Army Reserve on Active Duty Medical Hold
Enlisted
00F MOS Immaterial National Guard Bureau (NGB) 00G MOS Immaterial US Army Reserve (USAR) 00S Special Duty Assignment AFSC 00Z Command Sergeant Major 09B Trainee Unassigned 09C Trainee Language 09D College Trainee 09G Army National Guard (ARNG) on Active Duty Medical Hold 09H US Army Reserve (USAR) on Active Duty Medical Hold 09J GED Completion Program 09M March 2 Success 09N Nurse Corps Candidate 09R Simultaneous MBR Program 09S Commissioned Officer Candidate 09T College Student Army National Guard Officer Program 09U Prior Service or Branch Transfer without Defined MOS 09W Warrant Officer Candidate
Infantry Branch (IN)
Officer
11A Infantry Officer
Enlisted
11B Infantryman (includes soldiers formerly designated 11M [Mechanized] and 11H [Anti-armor]) 11B Infantryman is the basic infantry soldier MOS of the US Army. 11C Indirect Fire Infantryman (Mortarman) 11D Armor Reconnaissance Specialist 11E Armor Crewmen 11H Heavy Anti-armor Weapons Crewman 11M Fighting Vehicle Infantryman 11X Undetermined Infantry (Open Enlistment Option, B/C determined during training.) 11Z Infantry Senior Sergeant
Corps of Engineers Branch (EN)
Prior to 1999, the Engineer designations were 12 series and 83 series. In 1999, CMF 83 changed to CMF 51. In 2004, CMF 51 changed to CMF 21. In 2004, the engineer designation changed from 12 to 21. In 2009, the engineer designation was changed again, from CMF 21 to CMF 12. In 2013, the engineer officer designations 12B (Combat Engineer) and 12D (Facilities/Contract Construction Management Engineer (FCCME)) were consolidated into 12A.