Shoulder Sleeve Insignia
On a black disc 2 1/4 inches (5.72 cm) in diameter, a white circle 2 inches (5.08 cm) in diameter and 1/4 inch (.64 cm) in width.
A white circle was used as a corps badge by an organization designated I Corps during the Civil War. The white circle was selected as the identifying device for the current I Corps.
The shoulder sleeve insignia was approved by the Adjutant General, American Expeditionary Forces telegram on 3 December 1918 and approved by the War Department on 17 June 1922. (TIOH Drawing Number A-1-57)
Combat Service Identification Badge
A silver color metal and enamel device 2 inches (5.08 cm) in diameter consisting of a design similar to the shoulder sleeve insignia.
Distinctive Unit Insignia
A gold color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of an ultramarine blue volcano discharging a silver gray and red cloud of smoke and lava, superimposed by a gold "I", all upon a black annulet enclosing a white annulet with a central black disc; crossing the base is a gold scroll inscribed "AMERICA'S CORPS" in black letters.
The black disc with white ring is a direct representation of the I Corps shoulder sleeve insignia, which was approved in World War I. The volcanic mountain symbolizes the unit's World War II history in Australia, New Guinea, the Philippines, Japan and later service in Korea and at Fort Lewis - all within the Pacific geological "Ring of Fire." The blue on the mountain symbolizes the I Corps infantry composition and its relation with the Pacific Ocean. The flame and smoke refer to the I Corps' hardening in the fire of combat in WWI, WWII, and Korea. The numeral "I" refers to the unit designation and the fact I Corps was the first Army Corps into combat in two wars. The color gold signifies the high worth of the unit. The motto "America's Corps" is in reference to I Corps' large Reserve Component base, with units located throughout the United States.
The current distinctive unit insignia was approved on October 31, 1988. The original distinctive unit insignia for I Corps was approved on 8 June 1942. It was a blue disc with white star, a white Ionic column rising from a white pediment and a motto scroll with "Aspire." A new insignia was authorized on 21 May 1970, which was a hexagon elongated vertically and divided by a wavy black diagonal band with ten silver stars, between dark blue at the top with a yellow fleur-de-lis and a white star and a light blue area in base bearing a Korean Taeguk. A third design, which was a duplicate of the shoulder sleeve insignia was approved on 14 September 1982 and cancelled on 31 October 1988.