Support Battalion has the unique mission of supporting nearly every aspect of recruit training from the moment new recruits set foot on Parris Island until they graduate as Marines 13 weeks later.

Support Battalion personnel process all new recruits during their initial five days on Parris Island. Once in training, recruits come into regular contact with Support Battalion personnel who also teach a majority of the academic classes and qualify recruits in the Marine Corps Martial Arts Program and water survival.

Support Battalion consists of three companies that directly support recruit training.

Instructional Training Company - responsible for all the instructors who teach the academic classes, Marine Corps Martial Arts Program classes and water survival and administer the testing or qualification in those areas.

Recruit Processing Company - responsible for entry-level processing all recruits once they arrive on Parris Island as well as those recruits recommended for separation prior to completing training.

Special Training Company - responsible for recruits who have been injured in some capacity in training and need medical rehabilitation, physical conditioning and evaluation before continuing to train on Parris Island or follow-on training at the School of Infantry in North Carolina.