US Army Opens Search for M109 Replacement — 23 Armies Still Field 6,036 of the Cold War Howitzer

The US Army has formally opened its search for a successor to the M109 self-propelled howitzer, publishing a request for information on September 1, 2026 that seeks "a tracked self-propelled 155mm howitzer for employment within armored formations," Breaking Defense reported. Responses are due by September 11.

Shephard Media, which refers to the program as the Mobile Tactical Cannon-Tracked (MTC-T), forecasts a deal worth up to $8 billion for roughly 670 platforms. Both figures are the outlet's own projection: as Breaking Defense notes, the RFI itself specifies neither a contract value nor a quantity.

The tracked effort runs alongside a wheeled sibling. In August 2026, Hanwha Defense USA won a contract worth up to $233 million for wheeled Mobile Tactical Cannon prototypes, based on the K9 and aimed at replacing towed M777 howitzers. A Program Executive Office spokesperson told Breaking Defense the two variants "address different operational requirements and formations": the wheeled system is meant for formations that currently rely on towed artillery, while the tracked variant would accompany armored formations.

Whichever design is eventually selected will be stepping into the place of one of the most widely distributed artillery systems in service. First fielded in the 1960s, the M109 family still counts 6,036 self-propelled howitzers in active service across 23 countries in 2026, according to GlobalMilitary.net inventory data covering the world's armies.

The United States is itself the largest operator, with 1,521 guns on strength — 1,250 M109A6 Paladins alongside 271 of the newer M109A7. South Korea follows with 1,040 K55s, a license-built derivative of the M109. Six further armies field 250 or more:

• Pakistan — 438
• Greece — 420
• Jordan — 358
• Egypt — 325
• Morocco — 300
• Israel — 250

Taiwan (225), Iraq (220), Iran (150), Switzerland (133), Saudi Arabia (110), Brazil (109), Spain (96), Ukraine (90) and the United Arab Emirates (87) round out the operators below that threshold, with the remaining six countries accounting for 164 guns between them. The type's persistence is part of a wider pattern in ground-forces inventories examined in GlobalMilitary.net's analysis of the world's towed and self-propelled artillery fleets.

The scale of that installed base means the US program will be watched well beyond Washington: for two dozen armies, the M109 is not a legacy system but the backbone of their tube artillery.

The Army has scheduled an industry day for the week of September 8, ahead of the September 11 deadline for RFI responses.