Military Addresses Explained: APO, FPO and DPO

Address basics  |  April 1, 2026  |  2 min read

Mail for service members and diplomats overseas travels through the US postal system to a military or diplomatic post office. These addresses use a special format.

What the codes mean

• APO: Army Post Office, used by Army and Air Force installations.
• FPO: Fleet Post Office, used by Navy ships and Marine Corps units.
• DPO: Diplomatic Post Office, used by US embassies.

The state field

Instead of a state, military addresses use one of three codes:

• AA: Armed Forces Americas (excluding Canada)
• AE: Armed Forces Europe, Middle East, Africa and Canada
• AP: Armed Forces Pacific

Example format

• SGT JOHN SMITH
• UNIT 2050 BOX 4190
• APO AP 96278-2050

The city line is APO, FPO or DPO. Do not add the foreign city or country name, which can send the mail into a foreign postal system.

ZIP codes

Military ZIP codes start with 09 for AE, 340 for AA and 962 to 966 for AP.

For developers

If your store ships to military addresses, include AA, AE and AP in the state dropdown and allow APO, FPO and DPO as city values. Test that your shipping rules treat these as domestic USPS mail.