Information courtesy of the US Army Homepage - www.army.mil
The United States Army Reserve (USAR) is the federal reserve force of the United States Army. Together, the Army Reserve and the Army National Guard constitute the reserve components (RC) of the United States Army. The Army Reserve was formed in 1908 to provide a reserve of medical officers to the Army. After the First World War, under the National Defense Act on 4 June 1920, Congress reorganized the U.S. land forces by authorizing a Regular Army, a National Guard, and an Organized Reserve (Officers Reserve Corps and Enlisted Reserve Corps) of unrestricted size, which later became the Army Reserve.
Training in the United States Army is generally divided into two categories - individual and collective.
Basic training consists of 10 weeks followed by AIT (Advanced Individualized Training) where they receive training for their MOS (military occupational specialties) with the length of AIT school varying by the MOS. Some individuals MOS's range anywhere from 14-20 weeks of One Station Unit Training, (OSUT) which counts as basic and AIT. Support and other MOS hopefuls attend nine to eleven weeks of Basic Combat Training followed by Advanced Individual Training in their primary (MOS) at any of the numerous MOS training facilities around the country.
The length of time spent in AIT depends on the MOS of the soldier. (ex. 25B- IT Specialist MOS is 24 Weeks, 11B- Infantry 15-17 weeks). Depending on the needs of the Army, BCT is conducted at a number of locations. Two of the longest running are the Armor School at Fort Knox, Kentucky and the Infantry School at Fort Benning, Georgia. Following these basic and advanced training schools, soldiers may opt to continue on with their training and apply for an "ASI" which stands for "Additional Skill Identifier". The ASI allows the Army to take a wide ranging MOS and taper it into a more unique MOS. For instance, take a combat medic whose duties are to provide pre-hospital emergency care. With an ASI the medic can receive additional training and become a Cardiovascular Specialist, a Dialysis Specialist or even a Licensed Practical Nurse.
This training includes pre-commissioning training either at USMA, ROTC, or OCS. After commissioning, officers undergo branch specific training at the Basic Officer Leaders Course, (formerly called Officer Basic Course) which varies in time and location based on their future jobs. Further career development is available through the Army Correspondence Course Program.
Collective training takes place both at the unit's assigned station, but the most intensive collective training takes place at the three Combat Training Centers (CTC); the National Training Center (NTC) at Fort Irwin, California, the Joint Readiness Training Center (JRTC) at Fort Polk, Louisiana, and the Joint Multinational Training Center (JMRC) at the Hohenfels Training Area in Hohenfels, Germany.