Army Techniques Publication 4-02.43 remains generally consistent with FM 4-02.43 on key topics while adopting updated terminology and concepts, as necessary. Army Health System support to ARSOF is challenging in that ARSOF are lightly equipped with limited organic support assets. Therefore, they must be self-sustaining in all areas of medical care throughout the range of military operations. Since they routinely operate in undeveloped joint operational areas without established support systems, ARSOF medical personnel must assume both AHS missions of health service support (HSS) and force health protection (FHP) responsibilities. The purpose of Army Techniques Publication (ATP) 4-02.43 is to provide the authoritative doctrine for the Army Medical Department's (AMEDD's) Army Health System (AHS) support of Army special operations forces (ARSOF) as part of the protection and sustainment warfighting functions support to unified land operations. Army special operations forces are those Active Army and Reserve Component forces designated by the Secretary of Defense that are specifically organized, trained, and equipped to conduct and support special operations. The acronym ARSOF represents special forces (SF), special mission units, Rangers, civil affairs (CA), military information support operations (MISO), and Army special operations aviation forces assigned to the United States Army Special Operations Command (USASOC), which are all supported by the sustainment brigade (special operations) (airborne) (SB[SO][A]). This publication also discusses joint special operations and provides a limited discussion of other Services capabilities.