A Silver color metal and enamel device 1 5/32 inches (2.94 cm) in height, consisting of a shield blazoned: Gules, a chevron wavy between in sinister chief a horse's head erased and in base a mullet all Argent; on a canton Or an anchor debruised by two oars in saltire Gules. Above the shield on a wreath of the colors (Argent and Gules) a Gila monster statant Proper. Below the shield a Silver scroll inscribed "ASISTIREMOS" in Black letters.
The wavy chevron shows the service of the unit along the Rio Grande; the horse's head its mounted status. The star is the lone star of Texas. These charges with the color of the field are the Engineer colors, red and white. The canton shows the parent organization, the 2d Engineers, being taken from the arms of that regiment. The crest is a Gila monster, much in evidence in the Border country.
The distinctive unit insignia was originally approved for the 9th Engineers on 31 August 1925. It was amended to change the designation to Engineer Squadron on 3 April 1930. It was redesignated for the 9th Armored Engineer Battalion on 7 October 1942. It was redesignated again for the 9th Engineer Combat Battalion on 5 June 1952. The insignia was redesignated for the 9th Engineer Battalion on 15 November 1956.