10 U.S.C. § 7151 Commissioned officer grades
The commissioned grades in the Regular Army are:
(1) Major general.
(2) Brigadier general.
(3) Colonel.
(4) Lieutenant colonel.
(5) Major.
(6) Captain.
(7) First lieutenant.
(8) Second lieutenant.
USC Chapter 715
USC Chapter 715
in effect10 U.S.C. § 7152 General officers: title of office
An officer holding an appointment as a general officer in the Regular Army may be called a general officer in the Regular Army. In addition, a general officer of the Regular Army in the Medical Corps, Dental Corps, Veterinary Corps, Judge Advocate General’s Corps, or the Chaplains, may be called a general officer of that branch.
10 U.S.C. § 7153 Commissioned officers: appointment without specification of branch; transfer between branches
(a) Appointments in commissioned grades in the Regular Army shall be made without specification of branch except in each of the special branches and as professors or director of admissions of the United States Military Academy.
(b) Commissioned officers appointed in the Regular Army without specification of branch shall be assigned, and may be transferred and reassigned, by the Secretary of the Army to branches other than the special branches, according to their professional qualifications and the needs of the Army.