"When worn with medals, ribbons, or marksmanship badges, the bottom of the insignia will be centered 1/8 inch above the top row of such awards."

Full Regulations for Wear paragraph

a. Authorized insignia will be worn on the left breast of all service and dress coats. It may be worn at the individual's option on khaki shirts worn as the outer garment (with or without ribbons), utility coats or the maternity work uniform coats. Miniature insignia, one-half regular size, will be worn on evening dress jackets. Breast insignia will not be worn on the cloak/cape, AWC, extreme cold weather parka, tanker jacket, field coat or sweater.

b. Anodized breast insignia will be worn on all evening dress and dress uniforms. Either anodized or oxidized (also known as “antique” finish) breast insignia may be worn at the individual’s option on the service uniforms, but mixing of anodized and oxidized breast insignia is not authorized. Only anodized Marine Special Operator insignia will be worn on the dress and service uniforms. When breast insignia are worn on the utility uniform, anodized or oxidized breast insignia will be worn, with the exception that subdued brown or black breast insignia may be prescribed in a field environment in lieu of oxidized breast insignia. Only oxidized Marine Special Operator insignia will be worn on the utility uniform.

c. When worn on the dress coat, service coat, khaki shirt, or maternity tunic, the insignia will be placed with wings horizontal and parallel to the top of the breast pockets (if any). On women's coats and combat utility uniform coats with slanted pockets, a horizontal line tangent to the highest point of the pocket (or top corner of the service tape in the case of the combat utility uniform coat) is considered the top of the pocket (see figure 4-15).

      (1) When worn alone on the dress and service coats and shirts, the insignia will be worn in the same position a single ribbon would be worn.

      (2) When worn with medals, ribbons, or marksmanship badges, the bottom of the insignia will be centered 1/8 inch above the top row of such
awards. When successively decreasing rows of ribbon bars are worn (as in subparagraph 5301.5), and the top row of ribbons is such that centering the
insignia presents an unsatisfactory appearance, the insignia may be centered between the outer edge of the coat lapel and the left edge of the vertically
aligned ribbon rows.

d. When worn on male officers' evening dress jacket, the miniature insignia will be placed on the left-front panel on a line 1/8 inch above the second blind buttonhole, and spaced midway between the inner edge and left armhole seam.

e. When worn on evening dress jackets with lapels, the miniature insignia will be centered 1/8 inch above the miniature medals, or if no medals are authorized, the miniature insignia will be centered on the lapel at the position prescribed for the top of the medal bar.

f. Other U.S. service pilot/navigator insignia or foreign pilot insignia earned while the individual was a member of the foreign or other U.S. service may be worn provided the insignia is a duly authorized qualification insignia. These insignia may be worn on the right breast, in the same manner as Navy/Marine Corps insignia are worn on the left breast, without specific CMC authorization.

g. Other U.S. service pilot insignia earned as a Marine while undergoing training leading to qualification for the naval aviation insignia will be worn on the left breast as prescribed above, until qualified and authorized to wear the naval aviator insignia, at which time the other service insignia will no longer be worn.

h. When two Navy/Marine Corps aviation insignia are worn at a time, the senior insignia will be worn 1/8 inch above the other as follows (from top to
bottom):
    (1) Naval Aviator and Naval Aviation Pilot
    (2) Naval Flight Officer
    (3) Marine Aerial Navigator

    (4) UAS Officer
    (5) Combat Aircrew. Individual option, but may not be worn with Naval aircrew.
    (6) Naval Aircrew. Individual option, but may not be worn with combat aircrew.

    (7) Naval Aviation Observer
    (8) UAS Enlisted Operator

i. When the Navy/Marine Corps parachutist insignia is worn, the basic parachutist insignia will not be worn. When aviation insignia is worn with the basic or Navy/Marine Corps parachutist insignia, the parachutist insignia will be centered 1/8 inch above any aviation insignia.

j. When EOD insignia is worn with aviation or parachutist insignia, the EOD insignia will be centered 1/8 inch above the other insignia.k. A Marine with more than one diver insignia will wear the senior insignia, per the current edition of MCO P1000.6, ACTS Manual. When diver insignia are worn with any other breast insignia, the diver insignia will be centered 1/8 inch above the other insignia.

l. Not more than two USMC-approved breast insignia will be worn on the left, and not more than one foreign pilot or other U.S. service pilot/navigator insignia will be worn on the right, at any time. When the Marine Special Operator insignia is worn, no additional breast insignia is authorized for wear with this device.