The M998, M998A1, M1038 and M1038A1 HMMWVs are cargo/troop carrier configurations of the HMMWV family. They are used to transport equipment, materials, and/or personnel. The vehicles are equipped with basic armor and used to transport equipment, materials, and/or personnel. The cargo carrier configuration is capable of transporting a payload (including crew) of 2,500 pounds and the troop carrier is capable of transporting a two man crew and eight passengers. Both use a troop seat kit for troop transport operations. The cargo/troop carrier can also be configured in a four man crew configuration. The vehicles can climb 60% slopes and traverse a side slope of up to 40% fully loaded. The vehicles can ford hard bottom water crossing up to 30 inches without a deep water fording kit and up to 60 inches with the kit.

Fully-loaded M998, M998A1, M1038, and M1038A1 cargo/troop carriers will climb road grades as steep as 60% (31°) and traverse a side slope of up to 40% (22°). The vehicle fords hard bottom water crossing up to 30 inches (76 centimeters) without a deepwater fording kit and 60 inches (152 centimeters) with the kit.

The M1038, M1038A1 are equipped with the self-recovery winch which can also be used to recover like systems. The M998A1 and M1038A1 models have the latest modifications applied to the vehicles. The only difference between the M998 and M998A1 cargo/troop carriers and the M1038 and M1038A1 cargo/troop carriers is that the M998 and M998A1 do not have winches and the M1038 and M1038A1 do.

The M998 is the baseline vehicle for the M998 series of 1 1/4-ton trucks, which are known as the HMMWV vehicles. The HMMWV vehicles include 11 variants. They are: M998 Cargo/Troop Carrier; M1038 Cargo/Troop Carrier, with winch; M1043 Armament Carrier; M1044 Armament Carrier, with winch; M1045 TOW Carrier; M1046 TOW Carrier, with winch; M997 Ambulance, basic armor 4-Litter; M1035 Ambulance, 2-Litter; M1037 Shelter Carrier; M1042 Shelter Carrier, with winch; M1097 Heavy HMMWV (payload of 4,400 pounds). All HMMWVS are designed for use over all types of roads, in all weather conditions and are extremely effective in the most difficult terrain. The HMMWVS high power-to-weight ratio, four wheeled drive and high ground clearance combine to give it outstanding cross-country mobility.