The 77th Armor is an armored (tank) regiment of the United States Army. The 77th Armor Regiment is part of the U.S. Army Regimental System with only a single battalion, the 1st Battalion, 77th Armor Regiment, and is therefore classified as both a single battalion and the remainder of the Regiment itself. 1–77 AR is currently stationed at Fort Bliss, Texas as part of the 3rd Brigade "Bulldogs", 1st Armored Division and has transformed from a tank pure battalion into a combined arms battalion (CAB).

The United States Army Regimental System (USARS) is an organizational and classification system used by the United States Army. It was established in 1981 to replace the Combat Arms Regimental System (CARS) to provide each soldier with continuous identification with a single regiment, and to increase a soldier's probability of serving recurring assignments with their regiment. The USARS was intended to enhance combat effectiveness by providing the opportunity for a regimental affiliation, thus obtaining some of the benefits of the traditional regimental system.