A gold color metal and enamel device 1 3/16 inches (3.02 cm) in height overall consisting of a maroon heptagon bearing overall a Philippine sun with seven rays, the disc of the sun of blue and the rays gold and surmounted by a seven-pointed star of white charged throughout by a scarlet Geneva cross, the points of the star extending over the blue disc and between the gold rays of the sun.
The seven-pointed white star, suggested by the Australian flag, and bearing a scarlet Geneva cross refers to the activation of the organization in Australia as the 18th Portable Hospital (Provisional) 14 September 1942. The seven points of the star further allude to the 4 battle honors: Papua, New Guinea, Leyte and the assault landing at Luzon, (the point of the star bearing the scarlet arm of the cross simulating an arrowhead) and 3 decorations: Distinguished Unit Citation for Papua, Distinguished Unit Citation for Corregidor and Philippine Presidential Unit Citation for the period 17 October 1944 to 4 July 1945, awarded the organization in World War II. The two Distinguished Unit Citations are symbolized by the blue disc of the sun and the Philippine Presidential Unit Citation by the colors blue, white and red, the rays of the sun illuminating and glorifying the achievements of the unit. The number of rays of the sun (7), of the points of the star (7) and arms of the cross (4a) also add up to 18, the unit's numerical designation. The colors maroon and white are those used for the Army Medical Department.
The distinctive unit insignia was approved on 10 February 1969.