A gold color metal and enamel device 1 3/16 inches (3.02 cm) in height overall consisting of a gold demi-sunburst at the top and in base six stylized green eucalyptus leaves fanned out, overall a scarlet Greek cross with horizontal arm bearing a superimposed gold alligator, all above a semi-circular tri-folded maroon scroll inscribed "SERVE TREAT TRAIN" in gold letters.
The Greek cross, a symbol of aid and assistance, with the demi-sunburst alludes to the Hospital's location at Jacksonville in Florida, the "Sunshine State." The stylized eucalyptus leaves represent the eucalyptus tree, noted for its medicinal value, that is successfully grown in Florida. The alligator, found in Florida, is strong and long-living, while the gold sun rays symbolizing good health and healing all allude to the mission of the unit and to the location of the organization.
The distinctive unit insignia was originally approved for the 345th Evacuation Hospital on 6 August 1973. It was redesignated for the 345th Combat Support Hospital on 7 September 1976. Redesignated for the 345th Field Hospital on 17 April 2018.