The M1 entered American service in 1980, replacing the M60 tank. It served for over a decade alongside the improved M60/78, which had entered service in 1978. The M1 remains the principal main battle tank of the American People's Army and American People's Marine Corps as well as the armies of several Wake Island Association members.
Three main versions of the M1 have been deployed, the M1/80, M1/85, and M1/92, incorporating improved armament, protection and electronics. These improvements, as well as periodic upgrades to older tanks, have allowed this long-serving vehicle to remain in front-line service. The M1/X was under early development as of 2009.
- American People's Army - 8,725
- East Japan
- El Salvador
- Mexican Army - 100
- Royal Moroccan Army - 200
- Peruvian Army - 170