In the United States Army, soldiers may wear insignia to denote membership in a particular area of military specialism and series of functional areas. Army branch insignia is similar to the line officer and staff corps officer devices of the U.S. Navy as well as to the Navy enlisted rating badges. The Medical, Nurse, Dental, Veterinary, Medical Service, Medical Specialist, Chaplains, and Judge Advocate General's Corps are considered "special branches", while the others are "basic branches".

In the United States Navy, commissioned officers are either line officers or staff corps officers. Staff corps officers are specialists in career fields that are professions unto themselves, such as physicians, lawyers, civil engineers, chaplains, and supply specialists. For example, a physician can advance to become the commanding officer (CO) of a hospital, the medical hospital on a hospital ship or large warship, or a medical school; or the Chief of the Medical Corps or of the Bureau of Medicine and Surgery. A supply officer can become the CO of a supply depot or a school, or the head of the Naval Supply Systems Command, etc.