APO, FPO and DPO state codes and ZIP prefixes.

What APO, FPO and DPO mean

The Domestic Mail Manual, section 703, part 2.0, covers overseas military and diplomatic post office mail. A Military Post Office (MPO) is a branch of a U.S. civil post office operated by the Army, Navy, Air Force or Marine Corps to serve military personnel overseas or aboard ships. The term MPO includes Army Post Offices (APOs) for the Army and Air Force and fleet post offices (FPOs) for the Navy and Marine Corps. A Diplomatic Post Office (DPO) is the equivalent run through the U.S. Department of State for authorized federal employees stationed abroad, who pay domestic postage and are not subject to foreign customs clearance (section 3.1.1). The mail is domestic mail, which is why it uses a state abbreviation and a five-digit ZIP code.

The three state codes and their ZIP prefixes

Section 2.3.1 requires APO, FPO and DPO addresses to follow the domestic addressing standards in section 602 and to include the correct APO, FPO or DPO designation and AA (Armed Forces Americas), AE (Armed Forces Europe) or AP (Armed Forces Pacific). It says AA, AE and AP are used for addresses with the 3-digit ZIP Code prefixes 340, 090 to 098 and 962 to 966, respectively. So a ZIP code of 09400 is an AE address, 96691 is AP, and a ZIP starting with 340 is AA. The tool above only checks the prefix; it does not tell you whether a specific five-digit ZIP exists or is currently assigned, because the DMM does not list individual ZIP codes.

How to write the address

Line 1 is the full name or job title. Mail addressed to “Any Service Member”, “Any Soldier”, “Military Mail” and similar wording is prohibited. Line 2, the delivery line, must show one of the military address types: CPR (Consolidated Postal Room), OPC (Official Postal Center), PSC (Postal Service Center), UPR (Unit Postal Room) or UNIT, with the number and the box number when assigned. The last line holds APO or FPO (or DPO) as the “city”, the two-letter AA, AE or AP code as the “state”, and the ZIP or ZIP+4. The DMM’s examples are JOHN DOE, PSC 5698 BOX 2002, APO AE 09400 and SEAMAN JOHN DOE, UNIT 100100 BOX 4120, FPO AP 96691.

Do not add a foreign city or country

Section 2.3.1 says APO, FPO and DPO addresses must not include a foreign city or country name. Section 2.3.2 adds that mail showing a foreign city and country in addition to the APO, FPO or DPO designation is subject to the postage prices and conditions for international mail. In practice that means adding “Germany” or “Japan” to a military address can change how the item is priced and handled.

Restrictions worth knowing

Hazardous, restricted or perishable matter sent to, from or between APO, FPO and DPO destinations is subject to the International Mail Manual part 130, DMM 601, Publication 52 and the Department of Defense conditions listed in the Postal Bulletin (section 2.2.1). APO and FPO mail addressed to U.S. military or State Department retirees (Box R) is limited to 16 ounces and up to a 90-day supply of TRICARE medications, and retirees are not authorized DPO services (section 2.2.2). Size and weight follow the standards in DMM 201 unless limited further, and packages must meet the packaging standards in 601.1.0 through 601.9.0 (sections 2.4.1 and 2.4.2).

Worked examples

ZIP 09400: prefix 094 is inside 090 to 098, so the code is AE. ZIP 96691: prefix 966 is inside 962 to 966, so the code is AP. ZIP 34090: prefix 340, so AA. ZIP 10001: prefix 100 is not a military prefix and is an ordinary domestic ZIP. If you have the state code and need the ZIP range, the reverse is: AA is 340, AE is 090 to 098, AP is 962 to 966.

Limits of this page

The ZIP rule comes from the DMM text. We did not read Publication 28 for these prefixes: the Publication 28 military-address pages we tried returned not-found errors or no useful text. Confirm a specific unit address with the sender or the unit’s postal office, and use USPS tools for current prices. This is general information, not a delivery guarantee.

Sources

Sources opened and read November 2, 2026.

• USPS Domestic Mail Manual, 703 Special Standards, section 2.0 Overseas Military and Diplomatic Post Office Mail (read November 2, 2026)