A silver color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a Greek cross divided horizontally wavy maroon and blue, bearing a five-pointed silver star at its center, the cross surmounted at opposite sides of its vertical arm by two silver serpents and all encircled by a continuous red scroll, arched at the top and crossing the vertical arm inscribed "TO SERVE" and curving downwards behind the horizontal arms and passing through the looped tails of the serpents in base inscribed "AND CONSERVE" in silver letters.
Maroon and white are the colors used for Medical organizations. The serpents, attributes of Aesculapius, are symbolic of healing and medicine and together with the cross, a symbol of aid and assistance, allude to the basic mission of the 18th Field Hospital. The wavy blue area refers to their World War II service in the Pacific and the five-pointed star, symbolic of health and wisdom, is also indicative of the state of Texas, where the unit was first activated.
The distinctive unit insignia was approved on 16 February 1979.