Insignia Description
A gold color metal and enamel device 1 1/8 inches 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.

Symbolism
The black disc with white ring is a direct representation of the I Corps shoulder sleeve insignia. 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 that I Corps was the first Army Corps into combat in two wars. The 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.

History
The current insignia was approved on October 31, 1988. The original distinctive unit insignia for I Corps was approved on June 8, 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 May 21, 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 was approved on September 14, 1982 and cancelled on October 31, 1988 was a duplicate of the shoulder sleeve insignia.

Source: The US Army Institute of Heraldry