In the mid-1980's the US Army started looking for a replacement to its aging fleet of M35 & M44 series of 2 1/2 ton and M54, M809 and M939 series of 5 ton trucks.  Development contracts were then awarded to three companies to produce prototypes of a new series of standardized trucks.  One of the companies, Stewart & Stevenson Services, produced a truck based on the Austrian company Steyr's 12 M 18 truck and eventually won the first contract in 1991 to produce the US Military's new Family of Medium Tactical Vehicle (FMTV) fleet.  The 2 1/2 ton 4x4 truck variants were named the Light Medium Tactical Vehicle (LMTV) and the 5 ton trucks named the Medium Tactical Vehicle (MTV).  Stewart and Stevenson produced the vehicles until approximately 2010 when Oshkosh Defense took over production.

Many changes and upgrades were made after the initial vehicles/variants which also resulted in name designation changes. The trucks first produced (retroactively referred to as A0 vehicles) were followed by the upgraded versions A1 and A1R.  The A1 and A1R vehicles incorporated automotive improvements including upgraded engine, brakes and transmissions (among many other smaller changes). Other FMTV designations are the P1 (an A0 vehicle with early add-on armor protection), A1P1 (an A1 vehicle with early add-on armor) and A1P2 (able to be/or equipped with LTAS armor).

In approximately 2003, the first armored FMTV trucks were fitted with the field-applied (to the regular cab) Radian Armored Crew Kit (RACK) - also called the Crew Protection Kit (CPK).  Protection was then upgraded and simplified by the creation of the Low Signature Armored Cab (LSAC) armor package which was applied instead of the regular cab at the factory.  In 2006 the Long-Term Armor Strategy (LTAS) modular armoring solution was developed which utilizes an “A” (Basic) protection package with “B” kits that can mounted when additional armor is warranted.  LTAS is also flexible enough to be fitted with further armor upgrades.

As a side note, 2.5 ton LMTV truck chassis was used as the basis for the Caiman 4x4 Light" Multi-Role Protected Vehicle and the 5 ton MTV chassis was used as the basis for the M1220 Caiman 6x6 MRAP and M1230 Caiman Plus 6x6 MRAP.

Finally, as early as 2014 the US Military started the process of finding a replacement vehicle for the FMTV series.  After a long process, the Oshkosh FMTV A2 was developed, tested and accepted for service by the US Military. The US Army plans to start fielding the A2 models in June 2023.