The Special Operations Peculiar Modification (SOPMOD) kit is an accessory system for the M4A1 Carbine used by USSOCOM. The kit allows special forces operators to configure their weapons to individual preferences and mission requirements.
The program dates back to September 1989, when the Special Operations Special Technology (SOST) Modular Close Combat Carbine Project was founded. The Material Need Statement (MNS) was signed on May 1992, and by September of 1993, the Operational Requirements Document (ORD) for the program was validated. Responsibility for the program was then assigned to the Crane Division of the Naval Surface Warfare Center (NSWC-Crane).
The SOPMOD kit is composed mostly of non-developmental and commercial off-the-shelf (NDI/COTS) accessories packaged together to support four M4A1 carbines.