Shield
Azure, a Kentucky flint-lock rifle in bend with a powder-horn suspended therefrom, all Or.
Crest
That for the regiments and separate battalions of the Army Reserve: On a wreath of the colors Or and Azure, 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
I AM READY.
Shield
The shield is blue for Infantry and the rifle and powder-horn are representative of the allocation of the organization.
Crest
The crest is that of the United States Army Reserve.
The distinctive unit insignia was originally approved for the 399th Infantry Regiment, Organized Reserves on 21 April 1931. It was redesignated for the 399th Regiment, Army Reserve on 18 August 1960.