The 18th Theater Medical Command (18 TMC) is a US Army medical theater enabling command, which provides operational medical support to United States Army, Pacific. The headquarters was located on the Korean peninsula from 1984 until 2008, when it was relocated to Fort Shafter, Hawaii.
Originally activated at Fort Lee, Virginia in 1967 as the 18th Medical Brigade, it was the U.S. Army's third field army level medical headquarters activated, following the 7th Medical Brigade in 1965 and the 44th Medical Brigade in 1966.
On a shield, oblong in shape and arched at both sides, 3 inches (7.62cm) in height and 2 inches (5.08cm) in width, within a 1/8 inch (.32cm) white border a field of blue having a white-edged maroon sword throughout the center with point down and entwined about the blade two white zig-zag bands in the form of a figure eight.
The sword is in the color maroon, suggestive of human blood, and symbolic of the medical needs of an army. The zig-zag bands are in pure white to suggest bandaging and the antiseptic requirements of medical practice; by entwining the sword, they signify the support provided by the organization.
The shoulder sleeve insignia was originally approved for the 18th Medical Brigade on 25 October 1967. It was redesignated for the 18th Medical Command on 16 February 1984. (TIOH Drawing Number A-1-469)
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 reference the Staff of Aesculapius of the Medical Corps insignia, and the oak symbolizes 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.