Uniform jacket, shirt, overseas cap and visor of a USMC III. Air-wing Service C uniform for a captain. Jackets has the patch and aviator wings attached as well as three ribbons for the distinguished flying cross, the air medal Asiatic-Pacific Campaign Medal and American Campaign medal.

The service uniform consists of green and khaki colors. The present service uniform of the USMC for enlisted Marines was adopted in 1943 making it the oldest service uniform still in use by the United States armed forces. It is roughly equivalent in formality and function to a business suit.

It is the prescribed uniform when:

• serving on a court-martial
• attending appearance in criminal court (off installations).
• making official visits and calls on U.S. and foreign dignitaries, officials, and military officers.
• visiting the White House, except when in a tourist capacity, or on an occasion where another uniform is specified.
• reporting for duty onshore

Like the Blue Dress uniform, the service uniform is authorized for wear while on leave or liberty.

The service uniforms are designated:

• Service "A" (or Alpha) is the base uniform. It consists of a green coat, green trousers with khaki web belt, khaki long-sleeve button-up shirt, khaki tie, tie clasp, and black shoes. The coat is cut to be semi-form fitting, with ribbons and marksmanship badges worn on the left chest of the coat. Women wear a green necktab in place of the tie, pumps instead of shoes, and have the option of wearing a skirt instead of slacks. It is sometimes appropriate to remove the jacket while indoors.
• Service "B" (or Bravo) is identical to the "A" except the coat is removed. Ribbons may be worn on the shirt.
• Service "C" (or Charlie) is identical to the "B" except with a short-sleeve button-up shirt and no tie.

There are two types of authorized headwear for the service uniform. Both men and women may wear the green soft garrison cap, sometimes nicknamed a "piss cutter”. There is the option of wearing a peaked cap (called a barracks cover). The design of these covers had differed between women and men. However, in late 2013, the Commandant of the Marine Corps approved the Marine Corps Uniform Board's recommendation to adopt the male dress and service cap as the universal dress and service cap for all Marines, male and female. As on the Blue Dress uniform, officers wear rank insignia on the shoulder epaulettes of their jackets and the collars of their shirts, while enlisted personnel wear rank insignia sewn on their sleeves.

A green crewneck sweater (originally adopted from British Army and Royal Marines issue) in the same color shade as that of the trousers may be worn with the "B" and "C" uniforms. When wearing the crewneck sweater with the long sleeve khaki shirt, a tie is not required.