US Army Vehicle Designations

The Army has numbered its materiel under one nomenclature system since July 1925, now MIL-STD-1464A: an item name, a status prefix (M for a standard item, XM in development, T for pre-1960s test designs), a model number counted within each equipment category, and an optional modification suffix, A for an alteration of a standard item, E for an experimental one, so an M547A2E1 accepted for service becomes the M547A3. A number is unique only inside its category, which is why an M1 tank, carbine and helmet coexist, and why the Abrams and Bradley restarted the vehicle sequence at M1 and M2 while the running series stood in the M900s. M1A2 therefore reads "standard item, model 1, second alteration"; the SEPv3 after it is a program name, not nomenclature.

One lane per family, one dot per type entering service. The T-number era fills the 1940s, the single M sequence starts with the M113 and M109, and the Big Five of the early 1980s restart at M1 and M2. After that the dots thin and the names move instead: SEPv3, A4, A7 and DVHA1 are upgrades of 1980s hulls. The MRAP surge and the JLTV add the M1200s; the M10 Booker of 2024, billed as the first new combat vehicle in four decades, was cancelled within a year.

The tank line shows the system changing underneath it. The Sherman was standardized as the Medium Tank M4 from the T6 pilot in February 1942, and its A1 to A4 marked parallel plants and engines, not successive improvements; the E8 suspension test letter survived as the nickname Easy Eight. The T26E3 fielded in February 1945 became the M26 Pershing, and its re-engined M26E2 accumulated enough changes to earn a new number, M46, the first Patton, followed by the M47 (an M46 hull under the T42 turret) and the M48 christened in 1952. The M60 of 1959, developed as the XM60, was never officially a Patton, and the M48A5 of 1975 shows the modern path: XM736, then M48A3E1, then standardization. The XM1 became the M1 in 1980 and the XM1E1 the M1A1 in 1986; since the M1A2 the letters have stopped moving, and SEPv2, SEPv3 and the SEPv4 cancelled in September 2023 are package names, with the next tank designated M1E3.

The Bradley entered service in 1981 as the M2 infantry and M3 cavalry fighting vehicle, and its letters track rebuilds: the A2 added steel appliqué, the M2A2 ODS carried the Operation Desert Storm lessons from 1995, the A3 digitized the vehicle, and the A4 is the restored-power standard, an M2A3 or M2A2 ODS-SA rebuilt under both Engineering Change Proposals and first fielded in April 2022. The M113 was the T113E1 adopted in 1960. The Marines differ: the LVTP7 of 1972 became the AAV7A1 in 1984 and is giving way to the ACV; the Advanced Amphibious Assault Vehicle was renamed EFV in 2003 and cancelled in 2011. The Bradley replacement was the Next Generation Combat Vehicle in June 2018, the Optionally Manned Fighting Vehicle from October 2018, and the XM30 by the June 2023 award of two design contracts to General Dynamics and American Rheinmetall; in February 2026 Army leadership declined to sign its Milestone B decision.

The Interim Armored Vehicle competition picked the LAV III in 2000, the Army named it Stryker in February 2002, and each role took its own number in the M1126 to M1135 block, from the infantry carrier to the NBC reconnaissance vehicle; the M1128 mobile gun system retired in 2022. The double-V hull ordered in 2011 was a different vehicle in nomenclature terms, so the DVH roles took M1251 to M1257, and the 30 mm Dragoon tested as the XM1296 became the M1296; the DVHA1 standard approved in 2018 then returned to the A letter, M1256A1 ICVVA1. The light tanks read like the tanks: T22 → M8 Greyhound, T41E1 → M41 Walker Bulldog, XM551 → M551 Sheridan in 1967. The M10 Booker was the Mobile Protected Firepower vehicle, built by General Dynamics under a June 2022 contract, named in June 2023 and delivered from February 2024; the Army terminated it in June 2025 after 26 vehicles.

Wheeled vehicles take the most numbers because every body style is its own model. The HMMWV, in service from 1985, runs from the M998 cargo truck through the M1025 armament carrier to the M1113 expanded-capacity chassis, the M1114 up-armored car of 1996 and the current M1151 and M1152. The MRAP program of 2007 bought commercial mine-protected trucks in three categories and numbered them afterward: Force Protection's Cougar, ordered by the Marines in 2004, Navistar's MaxxPro as the M1224 and its Dash as the M1235, BAE's RG-33 family in the M1220s and M1230s, and Oshkosh's M-ATV, selected on 30 June 2009, as the M1240, M1240A1 with the underbody kit and M1277 with a remote weapon station. The JLTV, Oshkosh's L-ATV chosen on 25 August 2015, took four mission numbers, M1278 to M1281, before the A2 recompete went to AM General in 2023; in May 2025 the Army decided to stop buying both Humvees and JLTVs.

The towed guns carry the clearest trace of the 1960s reform: the 105 mm Howitzer M2A1 of 1941 was renamed M101 when the artillery series was folded into the common sequence, and the 155 mm Howitzer M1 became the M114. The XM198 became the M198 in 1979 and the XM777 the M777, a British-designed ultralight gun tested by the Army from 1998. The M109 of 1963 shows every suffix: A1 (1973) and A2 (1979) lengthened the barrel, A5 (1991) rearmed the reserve, A6 was designed as the M109A3E2 and named Paladin, and A7 was "M109A6 PIM" until type classification, with deliveries from April 2015. The XM1299 Extended Range Cannon Artillery prototype of 2019 kept its X: the Army cancelled it in March 2024. Rockets took ordinary vehicle numbers, the M270 of 1983 (the General Support Rocket System until November 1979) and the M142 HIMARS, in service from June 2005 on an M1140 truck.

Wartime tank destroyers were not tanks in the nomenclature but gun motor carriages, so they counted in their own series with the gun in the name: the 3-inch Gun Motor Carriage M10 of June 1942 (the T35 pilot), the 76 mm Gun Motor Carriage M18 (T70) and the 90 mm Gun Motor Carriage M36 (T71). The popular names are uneven: Jackson was assigned to the M36 by the Ordnance Department in November 1944 for publicity, and Wolverine appeared in Chrysler advertising but was never official nor used by US troops. The T28 shows the series bleeding into each other: authorized as a heavy tank, re-designated the 105 mm Gun Motor Carriage T95 in 1945, renamed Super Heavy Tank T28 in 1946. The Marines' M50 Ontos was officially the Rifle, Multiple 106 mm, Self-propelled, accepted in 1956 from the T165 pilot. The M10 number came back in 2023 on the Booker, described by the Army as an assault gun.