State abbreviations

Every official two-letter USPS postal abbreviation for the 50 states, Washington, D.C. and the US territories. Type a code or a name to look it up.

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All 50 state abbreviations

D.C. and territories

NameUSPS code
District of ColumbiaDC
Puerto RicoPR
GuamGU
U.S. Virgin IslandsVI
American SamoaAS
Northern Mariana IslandsMP

Frequently asked questions

What are the two-letter state abbreviations?

They are the postal codes the US Post Office introduced in October 1963 with ZIP codes, standardised to two capital letters without periods (for example CA, TX, NY). They are the abbreviations to use on envelopes and forms.

Which state abbreviations are easy to mix up?

The "M" states cause the most mistakes: MA (Massachusetts), MD (Maryland), ME (Maine), MI (Michigan), MN (Minnesota), MS (Mississippi), MO (Missouri) and MT (Montana). Also AK is Alaska while AR is Arkansas, and AL is Alabama.

What is the abbreviation for Washington, D.C.?

DC. Territories also have postal codes: PR (Puerto Rico), GU (Guam), VI (US Virgin Islands), AS (American Samoa) and MP (Northern Mariana Islands).

Why is Iowa IA and not IO?

The Post Office avoided codes that could be misread or clash with others. Canada's Ontario uses ON, and IA follows the pattern of first and last letters used for several states, such as KY for Kentucky and VT for Vermont.