Shield
Gules in base throughout a bridge of five arches Argent masoned of the field.
Crest
From a wreath Argent and Gules, a fleur-de-lis, the center petal Azure and outer petals of the second, fimbriated of the first and enfiled with a civic crown of four embattlements of the like.
Motto
ID PERFICIEMUS (We Shall Consummate The Task).
Shield
The shield is in the colors of the Corps of Engineers. The bridge symbolizes the unit strength and construction ability of the organization.
Crest
Scarlet and white are the colors used for the Corps of Engineers. The four embattlements from the civic crown refer to the four battle honors earned in Europe during World War II and the triparted colors of the fleur-de-lis symbolize the award of the Presidential Unit Citation and the two Meritorious Unit Commendations awarded during that period.
The coat of arms was originally approved for the 12th Engineer Battalion on 12 July 1941. It was redesignated for the 12th Engineer Combat Battalion on 9 November 1943. It was redesignated for the 12th Engineer Battalion on 28 March 1958. The insignia was amended to add a crest on 4 December 1972.