United States Postal Abbreviations for States (USPS two‑letter codes)

Format and common uses

Each state abbreviation consists of two uppercase letters, for example CA for California or NY for New York. The convention deliberately omits periods and longer traditional forms (such as Calif. or N.Y.). USPS abbreviations are used on envelopes, in electronic address fields, on driver's licenses and in many information systems to ensure consistency and compatibility with automated optical recognition and sorting equipment.

History and development

Before the modern two‑letter system, a variety of traditional and postal abbreviations coexisted. In the 1960s, as ZIP Codes and automated mail processing were introduced, the USPS standardized two‑letter codes to make addresses machine‑readable and to fit limited space on mailing labels and forms. Those two‑letter codes later became the de facto standard for many government and private databases and were adopted by international standards bodies when identifying U.S. subdivisions (commonly prefixed by the country code).

States and their two‑letter abbreviations

• Alabama — AL
• Alaska — AK
• Arizona — AZ
• Arkansas — AR
• California — CA
• Colorado — CO
• Connecticut — CT
• Delaware — DE
• Florida — FL
• Georgia — GA
• Hawaii — HI
• Idaho — ID
• Illinois — IL
• Indiana — IN
• Iowa — IA
• Kansas — KS
• Kentucky — KY
• Louisiana — LA
• Maine — ME
• Maryland — MD
• Massachusetts — MA
• Michigan — MI
• Minnesota — MN
• Mississippi — MS
• Missouri — MO
• Montana — MT
• Nebraska — NE
• Nevada — NV
• New Hampshire — NH
• New Jersey — NJ
• New Mexico — NM
• New York — NY
• North Carolina — NC
• North Dakota — ND
• Ohio — OH
• Oklahoma — OK
• Oregon — OR
• Pennsylvania — PA
• Rhode Island — RI
• South Carolina — SC
• South Dakota — SD
• Tennessee — TN
• Texas — TX
• Utah — UT
• Vermont — VT
• Virginia — VA
• Washington — WA
• West Virginia — WV
• Wisconsin — WI
• Wyoming — WY

Notes and distinctions

Although the list above covers the 50 states, USPS also defines two‑letter codes for the District of Columbia (DC), U.S. territories (for example PR for Puerto Rico, GU for Guam) and special military mail destinations (AA, AE, AP). In many contexts—especially international standards and data exchange—the state code is combined with the country code (for example US‑TX). When preparing addresses for mailing, follow USPS guidance for placement, capitalization and ZIP Code use to ensure reliable delivery.