DA Form 71 at a glance
What it is: DA Form 71 is the Oath of Office - Military Personnel, and its principal purpose is to create a record of the date of acceptance of appointment.
Who signs: Sign your full name as shown in the First Name, Middle Name and Last Name after I. The official administering the oath enters the Grade, component, or office and the Signature.
This form will be executed upon acceptance of appointment as an officer in the Army of the United States.
Whenever any person is elected or appointed to an office of honor or trust under the Government of the United States, he/she is required before entering upon the duties of his/her office, to take and subscribe the oath prescribed by 5 USC 3331.
10 USC 626 and 14309 eliminate the necessity of executing oath on promotion of officers.
Completion of form is mandatory. Failure to do so will cause the appointment to be invalid.
A filled-in DA Form 71 example: a new officer takes the oath
How to fill out DA Form 71, box by box
Appointment for which oath is being executed
Indicate the appointment for which oath is being executed by placing an "X" in appropriate box. Regular Army commissioned officers will also specify the branch of appointment when appointed in a special branch.
Under COMMISSIONED OFFICERS the boxes are REGULAR ARMY, ARMY OF THE UNITED STATES, WITHOUT COMPONENT, and RESERVE COMMISSIONED OFFICER. Under WARRANT OFFICERS the boxes are REGULAR ARMY, ARMY OF THE UNITED STATES, WITHOUT COMPONENT, and RESERVE WARRANT OFFICER.
Your name, Social Security Number and grade
After I, enter your First Name, Middle Name and Last Name, and your Social Security Number.
The SSN is used to identify the member.
Enter the grade in which you have been appointed an officer in the Army of the United States.
Signature
Sign to swear (or affirm). I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic, that I will bear true faith and allegiance to the same. I take this obligation freely, without any mental reservation or purpose of evasion. I will well and faithfully discharge the duties of the office upon which I am about to enter. SO HELP ME GOD.
Sworn to and subscribed before me
After SWORN TO AND SUBSCRIBED BEFORE ME AT, fill in the line, then the Day, Month and Year after THIS DAY OF.
Official administering the oath
The official administering the oath enters the Grade, component, or office and the Signature.
The oath of office may be taken before any commissioned officer of any component of any Armed Force, whether or not on active duty (10 USC 1031), or before any commissioned warrant officer when acting as an adjutant, assistant adjutant, acting adjutant, or personnel adjutant in any of the Armed Forces (See UCM, Article 136; 10 USC 936). A commissioned warrant officer administering the oath of office will show his/her title in the block to the left of his/her signature.
The oath of office may also be taken before any civil officer who is authorized by the laws of the United States or by the local municipal law to administer oaths, and if so administered by a civil official, the oath must bear the official seal of the person administering the oath, or if a seal is not used by the official, the official's capacity to administer oaths must be certified to under seal by a clerk or court or other proper local official.
Common questions about DA Form 71
Where do I file it?
Immediately upon receipt of notice of appointment, the appointee will, in case of acceptance of the appointment, return to the agency from which received, the oath of office (on this form) properly filled in, subscribed and attested. In case of non-acceptance, the notice of appointment will be returned to the agency from which received, (by letter) indicating the fact of non-acceptance.
Sources
[1] DA Form 71 (JUL 1999), Oath of Office - Military Personnel, U.S. Army (the Official source link on this page).