USMC Ribbons are authorized on Marine dress “B”, dress “A” or shirts when prescribed as an outer garment. They are normally worn in rows of 3 or rows of 4 when displaying a large number of awards. If the lapel conceals any ribbons, they may be placed in successively decreasing rows, i.e., 4, 3, 2, 1. All aligned vertically on center, except if the top row can be altered to present the neatest appearance. Ribbon rows may be spaced 1/8 inch apart or together. Ribbon bars are centered 1/8 inch above the upper left pocket. When marksmanship badges are worn, the ribbon bars are 1/8 inch above them.
Marines may wear up to four medals side by side on a 3 inch bar. A maximum of seven medals may be overlapped (not to exceed 50% with the right or inboard medal shown in full). Full size medals on the blue or white dress jacket are centered on the left breast pocket with the upper edge of the holding bar on line midway between the 1st and 2nd button of the jacket. When large medals are worn, all unit citations and ribbons with no medals authorized are centered over the right breast pocket the bottom edge 1/8 inch above the top of the pocket.
For men, the maximum width of the holding bar for large medals is 5-1/2 inches, and the length of the medals from top of holding bar to bottom of medallions is 3-1/4 inches. A maximum of four large medals side by side will fit on the maximum width of holding bar; however, a maximum of seven medals will fit on the holding bar if overlapped. The overlapping on each row is equal (not to exceed 50 percent). The right or inboard medal shows in full.
Women wear no more than three large medals side by side on a single holding bar not to exceed 4-1/8 inches; however, a maximum of five medals will fit on the holding bar if overlapped.
When miniature medals are worn, no ribbons will be worn. On evening dress jackets miniature medals will be centered on the left front jacket panel midway between the inner edge and the left armhole seam, with the top of the bar on line with the 2nd blind button hole. On mess dress and SNCO’s evening and mess dress, the miniature medals are centered on the left lapel with the top of the holding bar 1 inch below the lapel notch. Maximum of 10 overlapped.How USMC Medals are Worn and Displayed,