ShieldGules (Brick Red) on a fess wavy Argent between in chief a key fesswise, wards downward Or and in base a wheel of the like a barrulet wavy Azure.
CrestThat for the regiments and separate battalions of the California Army National Guard: From a wreath Or and Gules, the setting sun behind a grizzly bear passant on a grassy field all Proper.
MottoFORWARD WITH THE BEST.
ShieldBuff (yellow) and brick red are the colors traditionally associated with Supply and Transport, the branch of the original unit. The key refers to the Battalion's basic mission; the wheel alludes to transport, one of the functions of the former organization. The two wavy bands, representative of water, symbolize service in the Philippines during World War II and in Korea by elements of the former organization.
CrestThe crest is that of the California Army National Guard.
The coat of arms was originally approved for the 40th Supply and Transport Battalion on 8 December 1976. It was redesignated for the 40th Support Battalion with blazon and symbolism revised effective 1 June 1987. The insignia was revised to change the motto on 10 May 1990. It was amended to correct the blazon of the crest (delete the crest of Nevada) on 18 August 2010.