A gold color metal and enamel device 1 1/8 inches (2.86 cm) in height overall, consisting of a light blue field behind two blue mountain peaks all enclosed by a crimson circular belt folded at top, buckled at bottom, inscribed "MAINTAIN" at left, "FOR" at top and "FREEDOM" at right in gold letters; overall a crimson four-bastioned fort one point up superimposed by a gold hammer and white lightning bolt crossed diagonally.
Crimson and light blue are traditionally associated with Maintenance units, colors of the parent organization. Gold is symbolic of excellence. The fort represents Fort Frederick, an historic stronghold important in the military past of Maryland. The two peaks are symbolic of the mountains of Maryland and identify with the home area of the organization. The colors of the device reflect the heritage of the unit. The hammer, a dual purpose tool and weapon, is emblematic of military technology and the maintenance of weapon systems. The lightning bolt alludes to rapid response to operational requirements, including mobilization for State and Federal emergency duties. Unity, teamwork and solidarity, prerequisites of combat readiness, are represented by the buckled, circular belt.
The distinctive unit insignia was originally approved for the 729th Maintenance Battalion on 5 July 1988. It was redesignated for the 729th Support Battalion, with description and symbolism revised on 28 September 1992.