A gold color and metal device 1 1/8 inches (2.86 cm) in height overall consisting of a gold rayed background rounded at the top and bearing a maroon Greek cross surmounted by a white inverted equilateral triangle charged with a red (scarlet) heraldic rose with gold details, the lower angle (or apex) of the triangle contained within the lower arm of the cross and the other two angles and horizontal side (or base) extending slightly above the horizontal arms of the cross, all above a semi-circular gold scroll lined scarlet inscribed "SAVE AND SUPPORT" in black letters, the scroll ends turned back and down at the ends of the horizontal arms of the cross and passing under the gold semi-circular part of the scroll.

The equilateral triangle alludes to the ability of the 99th Field Hospital to function as one unit or three separate hospital units.  The heraldic red rose of Lancaster symbolizes the location of the unit at Lancaster, Pennsylvania.  The Greek cross is a symbol of aid and assistance while the gold sun rays allude to health and healing.  Maroon and white are colors used by the Medical Department.

The distinctive unit insignia was approved on 15 June 1970.