Shield
Per saltire Gules and Or, three fleurs-de-lis, one in chief and two in fess counterchanged.
Crest
That for the regiments and separate battalions of the Army Reserve: On a wreath of the colors (Or and Gules) the Lexington Minute Man Proper. The statue of the Minute Man, Captain John Parker (H.H. Kitson, sculptor) stands on the Common in Lexington, Massachusetts.
Motto
FULMINIS INSTAR (Like Lightning).
Shield
The colors of the shield, red and yellow, are for Artillery, the previous designation of the unit. The fleurs-de-lis represent the unit's service in Europe during World War II.
Crest
The crest is that of the Army Reserve.
The coat or arms was originally approved for the 387th Field Artillery, Organized Reserve on 20 November 1936. It was redesignated for the 387th Field Artillery Battalion, Organized Reserve on 15 September 1942. A new design was approved for the 387th Field Artillery Battalion, Army Reserve on 10 September 1954. The authorization was amended to correct the wording to read "The coat of arms is amended by the addition of charges" on 3 March 1958. The coat of arms was redesignated for the 104th Regiment, Army Reserve on 18 August 1960.