(a) Every registrant who is or who becomes by enlistment or appointment, a commissioned officer, a warrant officer, a pay clerk, an enlisted man or an aviation cadet of the Regular Army, the Navy, the Air Force, the Marine Corps, the Coast Guard, the National Oceanic and Atmospheric Administration or the Public Health Service.

(b) Every registrant who is a cadet, United States Military Academy; or midshipman, United States Naval Academy; or a cadet, United States Air Force Academy; or cadet, United States Coast Guard Academy.

(c) Every registrant who by induction becomes a member of the Army of the United States, the United States Navy, the United States Marine Corps, the Air Force of the United States, or the United States Coast Guard.

(d) Exclusive of periods for training only, every registrant who is a member of a reserve component of the Armed Forces and is on active duty, and every member of the reserve of the Public Health Service on active duty and assigned to staff the various offices and bureaus of the Public Health Service including the National Institutes of Health, or assigned to the Coast Guard, the Bureau of Prisons of the Department of Justice, Environmental Protection Agency, or the National Oceanic and Atmospheric Administration or who are assigned to assist Indian tribes, groups, bands, or communities pursuant to the Act of August 5, 1954 (68 Stat. 674), as amended.