A device of gold color metal and enamel 1 1/8 inches (2.86cm) in height consisting of a gold sun of eighteen rays bearing in center a maroon Maltese Cross all centered on a gold disc scored with concentric rays and enclosed by a maroon motto scroll bearing the words "Trust, Labor, Courage" in gold letters; over the lower half of the scroll a wreath of gold oak leaves entwined by two white serpents their tails crossed in center, their heads raised at either side and facing outward.
The gold sun and maroon cross are symbolic of the support provided by the organization. The Maltese Cross is the symbol of the Knights of Malta, also called Knights Hospitaler, Knights of St. John and Order of the Hospital of St. John, which grew out of a hospital established in the 11th Century to care for pilgrims in the Holy Land. The eighteen rays of the sun allude to the unit's numerical designation. The serpents are a reference to the Staff of Aesculapius of the Medical Corps insignia and the oak is a symbol of strength.
The distinctive unit insignia was originally approved for the 18th Medical Brigade on 29 February 1968. It was redesignated on 16 February 1984 for the 18th Medical Command.